first commit
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65
java/search/BinarySearch.java
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65
java/search/BinarySearch.java
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@@ -0,0 +1,65 @@
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package search;
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/**
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* @author Nikita Doschennikov (me@fymio.us)
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*/
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public class BinarySearch {
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public static void main(String[] args) {
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IntList a = new IntList();
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int x = Integer.parseInt(args[0]);
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int n = args.length;
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for (int i = 1; i < n; i++) {
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a.put(Integer.parseInt(args[i]));
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}
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System.out.println(searchRecursive(x, a));
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// System.out.println(searchIterative(x, a));
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}
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static int searchIterative(int x, IntList a) {
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if (a.getLength() == 0) {
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return 0;
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}
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int low = 0,
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high = a.getLength() - 1;
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while (low <= high) {
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int mid = low + (high - low) / 2;
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if (a.get(mid) <= x) {
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high = mid - 1;
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} else {
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low = mid + 1;
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}
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}
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return low;
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}
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static int searchRecursive(int x, IntList a) {
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return searchRecursiveHelper(x, a, 0, a.getLength() - 1);
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}
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private static int searchRecursiveHelper(
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int x,
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IntList a,
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int low,
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int high
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) {
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if (low > high) {
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return low;
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}
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int mid = low + (high - low) / 2;
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if (a.get(mid) <= x) {
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return searchRecursiveHelper(x, a, low, mid - 1);
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} else {
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return searchRecursiveHelper(x, a, mid + 1, high);
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}
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}
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}
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50
java/search/BinarySearch3233.java
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50
java/search/BinarySearch3233.java
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@@ -0,0 +1,50 @@
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package search;
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/**
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* @author Nikita Doschennikov (me@fymio.us)
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*/
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public class BinarySearch3233 {
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public static void main(String[] args) {
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IntList a = new IntList();
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for (String arg : args) {
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a.put(Integer.parseInt(arg));
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}
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// System.out.println(searchIterative(a));
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System.out.println(searchRecursive(a, 0, a.getLength() - 1));
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}
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static int searchIterative(IntList a) {
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int arrLength = a.getLength();
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if (arrLength <= 1) return 0;
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int low = 0, high = arrLength - 1;
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while (low < high) {
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int mid = low + (high - low) / 2;
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if (a.get(mid) < a.get(arrLength - 1)) {
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high = mid;
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} else {
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low = mid + 1;
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}
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}
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return low;
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}
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static int searchRecursive(IntList a, int low, int high) {
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if (low >= high) {
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return low;
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}
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int mid = low + (high - low) / 2;
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if (a.get(mid) < a.get(a.getLength() - 1)) {
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return searchRecursive(a, low, mid);
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} else {
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return searchRecursive(a, mid + 1, high);
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}
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}
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}
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48
java/search/BinarySearch3435.java
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48
java/search/BinarySearch3435.java
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@@ -0,0 +1,48 @@
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package search;
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/**
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* @author Nikita Doschennikov (me@fymio.us)
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*/
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public class BinarySearch3435 {
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public static void main(String[] args) {
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IntList a = new IntList();
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for (String arg : args) {
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a.put(Integer.parseInt(arg));
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}
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// System.out.println(searchIterative(a));
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System.out.println(searchRecursive(a, 0, a.getLength() - 1));
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}
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static int searchIterative(IntList a) {
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int arrLength = a.getLength();
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if (arrLength <= 1) return 0;
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int low = 0, high = arrLength - 1;
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while (low < high) {
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int mid = low + (high - low) / 2;
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if (a.get(mid) > a.get(arrLength - 1)) {
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high = mid;
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} else {
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low = mid + 1;
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}
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}
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return low;
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}
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static int searchRecursive(IntList a, int low, int high) {
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if (low >= high) {
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return low;
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}
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int mid = low + (high - low) / 2;
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if (a.get(mid) > a.get(a.getLength() - 1)) {
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return searchRecursive(a, low, mid);
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} else {
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return searchRecursive(a, mid + 1, high);
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}
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}
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}
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77
java/search/BinarySearch3637.java
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77
java/search/BinarySearch3637.java
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@@ -0,0 +1,77 @@
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package search;
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/**
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* @author Nikita Doschennikov (me@fymio.us)
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*/
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public class BinarySearch3637 {
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public static void main(String[] args) {
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IntList a = new IntList();
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int x = Integer.parseInt(args[0]);
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int n = args.length;
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for (int i = 1; i < n; i++) {
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a.put(Integer.parseInt(args[i]));
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}
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// System.out.println(rightBoundIterative(x, a) - leftBoundIterative(x, a));
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System.out.println(
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rightBoundRecursive(x, a, 0, a.getLength() - 1) -
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leftBoundRecursive(x, a, 0, a.getLength() - 1)
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);
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}
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static int leftBoundIterative(int x, IntList a) {
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int low = 0,
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high = a.getLength() - 1;
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while (low <= high) {
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int mid = low + (high - low) / 2;
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if (a.get(mid) > x) {
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low = mid + 1;
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} else {
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high = mid - 1;
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}
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}
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return high + 1;
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}
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static int rightBoundIterative(int x, IntList a) {
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int low = 0,
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high = a.getLength() - 1;
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while (low <= high) {
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int mid = low + (high - low) / 2;
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if (a.get(mid) >= x) {
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low = mid + 1;
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} else {
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high = mid - 1;
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}
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}
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return high + 1;
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}
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static int leftBoundRecursive(int x, IntList a, int low, int high) {
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if (low > high) {
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return high + 1;
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}
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int mid = low + (high - low) / 2;
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if (a.get(mid) > x) {
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return leftBoundRecursive(x, a, mid + 1, high);
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} else {
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return leftBoundRecursive(x, a, low, mid - 1);
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}
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}
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static int rightBoundRecursive(int x, IntList a, int low, int high) {
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if (low > high) {
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return high + 1;
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}
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int mid = low + (high - low) / 2;
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if (a.get(mid) >= x) {
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return rightBoundRecursive(x, a, mid + 1, high);
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} else {
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return rightBoundRecursive(x, a, low, mid - 1);
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}
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}
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}
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77
java/search/BinarySearch3839.java
Normal file
77
java/search/BinarySearch3839.java
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@@ -0,0 +1,77 @@
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package search;
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/**
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* @author Nikita Doschennikov (me@fymio.us)
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*/
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public class BinarySearch3839 {
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public static void main(String[] args) {
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IntList a = new IntList();
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int x = Integer.parseInt(args[0]);
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int n = args.length;
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for (int i = 1; i < n; i++) {
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a.put(Integer.parseInt(args[i]));
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}
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int leftBound = leftBoundIterative(x, a);
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int rightBound = rightBoundIterative(x, a);
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int range = rightBound - leftBound;
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System.out.println(leftBound + " " + range);
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}
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static int leftBoundIterative(int x, IntList a) {
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int low = 0,
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high = a.getLength() - 1;
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while (low <= high) {
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int mid = low + (high - low) / 2;
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if (a.get(mid) > x) {
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low = mid + 1;
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} else {
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high = mid - 1;
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}
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}
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return high + 1;
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}
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static int rightBoundIterative(int x, IntList a) {
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int low = 0,
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high = a.getLength() - 1;
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while (low <= high) {
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int mid = low + (high - low) / 2;
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if (a.get(mid) >= x) {
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low = mid + 1;
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} else {
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high = mid - 1;
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}
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}
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return high + 1;
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}
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static int leftBoundRecursive(int x, IntList a, int low, int high) {
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if (low > high) {
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return high + 1;
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}
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int mid = low + (high - low) / 2;
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if (a.get(mid) > x) {
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return leftBoundRecursive(x, a, mid + 1, high);
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} else {
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return leftBoundRecursive(x, a, low, mid - 1);
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}
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}
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static int rightBoundRecursive(int x, IntList a, int low, int high) {
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if (low > high) {
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return high + 1;
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}
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int mid = low + (high - low) / 2;
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if (a.get(mid) >= x) {
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return rightBoundRecursive(x, a, mid + 1, high);
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} else {
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return rightBoundRecursive(x, a, low, mid - 1);
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}
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}
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}
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180
java/search/BinarySearchTest.java
Normal file
180
java/search/BinarySearchTest.java
Normal file
@@ -0,0 +1,180 @@
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package search;
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import base.MainChecker;
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import base.Runner;
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import base.Selector;
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import base.TestCounter;
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import java.util.Arrays;
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import java.util.List;
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import java.util.function.Consumer;
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import java.util.function.Function;
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import java.util.stream.IntStream;
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import java.util.stream.Stream;
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import static java.util.stream.IntStream.range;
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/**
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* @author Georgiy Korneev (kgeorgiy@kgeorgiy.info)
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*/
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public final class BinarySearchTest {
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public static final int[] SIZES = {5, 4, 2, 1, 10, 50, 100, 200, 300};
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public static final int[] VALUES = new int[]{5, 4, 2, 1, 0, 10, 100, Integer.MAX_VALUE / 2};
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private BinarySearchTest() {
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}
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// === Base
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/* package-private */ static int base(final int c, final int x, final int[] a) {
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return IntStream.range(0, a.length).filter(i -> Integer.compare(a[i], x) != c).findFirst().orElse(a.length);
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}
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// === 3637
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private static int count(final int c, final int x, final int[] a) {
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return (int) range(0, a.length).filter(i -> a[i] == x).count();
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}
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// === 3839
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private static String span(final int c, final int x, final int[] a) {
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final int begin = range(0, a.length).filter(i -> a[i] == x || Integer.compare(x, a[i]) == c).findFirst().orElse(a.length);
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final long length = range(0, a.length).filter(i -> a[i] == x).count();
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return begin + " " + length;
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}
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// === 3435
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private static Consumer<TestCounter> shift(final String name, final Kind kind) {
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final Sampler sampler = new Sampler(kind, false, false);
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return variant(name, variant -> {
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for (final int s : SIZES) {
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final int size = s > 3 * TestCounter.DENOMINATOR ? s / TestCounter.DENOMINATOR : s;
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for (final int max : VALUES) {
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final int[] a = sampler.sample(variant, size, max);
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for (int k = 0; k < a.length; k++) {
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variant.test(k, a);
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final int last = a[a.length - 1];
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System.arraycopy(a, 0, a, 1, a.length - 1);
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a[0] = last;
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}
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}
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}
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});
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}
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// === Common code
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public static final Selector SELECTOR = new Selector(BinarySearchTest.class)
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.variant("Base", Solver.variant0("", Kind.DESC, BinarySearchTest::base))
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.variant("3637", Solver.variant0("3637", Kind.DESC, BinarySearchTest::count))
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.variant("3839", Solver.variant0("3839", Kind.DESC, BinarySearchTest::span))
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.variant("3435", shift("3435", Kind.DESC))
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.variant("3233", shift("3233", Kind.ASC))
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;
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public static void main(final String... args) {
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SELECTOR.main(args);
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}
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/* package-private */ static Consumer<TestCounter> variant(final String name, final Consumer<Variant> variant) {
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final String className = "BinarySearch" + name;
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return counter -> variant.accept(new Variant(counter, new MainChecker(Runner.packages("search").args(className))));
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}
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/* package-private */ interface Solver {
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static Consumer<TestCounter> variant0(final String name, final Kind kind, final Solver solver) {
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return variant(name, kind, true, solver);
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}
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static Consumer<TestCounter> variant1(final String name, final Kind kind, final Solver solver) {
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return variant(name, kind, false, solver);
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}
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private static Consumer<TestCounter> variant(final String name, final Kind kind, final boolean empty, final Solver solver) {
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final Sampler sampler = new Sampler(kind, true, true);
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return BinarySearchTest.variant(name, vrt -> {
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if (empty) {
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solver.test(kind, vrt);
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}
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solver.test(kind, vrt, 0);
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for (final int s1 : SIZES) {
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final int size = s1 > 3 * TestCounter.DENOMINATOR ? s1 / TestCounter.DENOMINATOR : s1;
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for (final int max : VALUES) {
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solver.test(kind, vrt, sampler.sample(vrt, size, max));
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}
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||||
}
|
||||
});
|
||||
}
|
||||
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private static int[] probes(final int[] a, final int limit) {
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return Stream.of(
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Arrays.stream(a),
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IntStream.range(1, a.length).map(i -> (a[i - 1] + a[i]) / 2),
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IntStream.of(
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0, Integer.MIN_VALUE, Integer.MAX_VALUE,
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a.length > 0 ? a[0] - 1 : -1,
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a.length > 0 ? a[a.length - 1] + 1 : 1
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||||
)
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)
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.flatMapToInt(Function.identity())
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.distinct()
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.sorted()
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.limit(limit)
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.toArray();
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}
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Object solve(final int c, final int x, final int... a);
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default void test(final Kind kind, final Variant variant, final int... a) {
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test(kind, variant, a, Integer.MAX_VALUE);
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}
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||||
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default void test(final Kind kind, final Variant variant, final int[] a, final int limit) {
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for (final int x : probes(a, limit)) {
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variant.test(solve(kind.d, x, a), IntStream.concat(IntStream.of(x), Arrays.stream(a)));
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}
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||||
}
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||||
}
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||||
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public enum Kind {
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ASC(-1), DESC(1);
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||||
|
||||
public final int d;
|
||||
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Kind(final int d) {
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this.d = d;
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}
|
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}
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public record Variant(TestCounter counter, MainChecker checker) {
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||||
void test(final Object expected, final IntStream ints) {
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final List<String> input = ints.mapToObj(Integer::toString).toList();
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checker.testEquals(counter, input, List.of(expected.toString()));
|
||||
}
|
||||
|
||||
public void test(final Object expected, final int[] a) {
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||||
test(expected, Arrays.stream(a));
|
||||
}
|
||||
}
|
||||
|
||||
public record Sampler(Kind kind, boolean dups, boolean zero) {
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||||
public int[] sample(final Variant variant, final int size, final int max) {
|
||||
final IntStream sorted = variant.counter.random().getRandom().ints(zero ? size : Math.max(size, 1), -max, max + 1).sorted();
|
||||
final int[] ints = (dups ? sorted : sorted.distinct()).toArray();
|
||||
if (kind == Kind.DESC) {
|
||||
final int sz = ints.length;
|
||||
for (int i = 0; i < sz / 2; i++) {
|
||||
final int t = ints[i];
|
||||
ints[i] = ints[sz - i - 1];
|
||||
ints[sz - i - 1] = t;
|
||||
}
|
||||
}
|
||||
return ints;
|
||||
}
|
||||
}
|
||||
}
|
||||
48
java/search/IntList.java
Normal file
48
java/search/IntList.java
Normal file
@@ -0,0 +1,48 @@
|
||||
package search;
|
||||
|
||||
import java.util.Arrays;
|
||||
|
||||
/**
|
||||
* @author Nikita Doschennikov (me@fymio.us)
|
||||
*/
|
||||
public class IntList {
|
||||
|
||||
protected int[] list = new int[8];
|
||||
protected int idx = 0;
|
||||
|
||||
public IntList() {}
|
||||
|
||||
public IntList(int[] list) {
|
||||
this.list = list;
|
||||
}
|
||||
|
||||
public void put(int val) {
|
||||
if (idx >= list.length) {
|
||||
list = Arrays.copyOf(list, list.length * 2);
|
||||
}
|
||||
|
||||
list[idx++] = val;
|
||||
}
|
||||
|
||||
public int getLength() {
|
||||
return idx;
|
||||
}
|
||||
|
||||
public int get(int index) {
|
||||
return list[index];
|
||||
}
|
||||
|
||||
public String toString() {
|
||||
StringBuilder sb = new StringBuilder();
|
||||
|
||||
for (int i = 0; i < idx; i++) {
|
||||
if (i == idx - 1) {
|
||||
sb.append(String.valueOf(list[i]) + "\n");
|
||||
} else {
|
||||
sb.append(String.valueOf(list[i]) + " ");
|
||||
}
|
||||
}
|
||||
|
||||
return sb.toString();
|
||||
}
|
||||
}
|
||||
7
java/search/package-info.java
Normal file
7
java/search/package-info.java
Normal file
@@ -0,0 +1,7 @@
|
||||
/**
|
||||
* Tests for <a href="https://www.kgeorgiy.info/courses/paradigms/homeworks.html#java-binary-search">Binary Search</a> homework
|
||||
* of <a href="https://www.kgeorgiy.info/courses/paradigms/">Paradigms of Programming</a> course.
|
||||
*
|
||||
* @author Georgiy Korneev (kgeorgiy@kgeorgiy.info)
|
||||
*/
|
||||
package search;
|
||||
Reference in New Issue
Block a user