update

1/D/Main.java

@@ -0,0 +1,139 @@
+import java.util.*;
+import java.io.*;
+
+public class Main {
+  static int m;
+
+  public static void main(String[] args) throws IOException {
+    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    StringTokenizer st = new StringTokenizer(br.readLine());
+    int n = Integer.parseInt(st.nextToken());
+    m = Integer.parseInt(st.nextToken());
+
+    int totalMasks = 1 << m;
+
+    int[][] maskPatterns = new int[totalMasks][];
+    int[] maskSize = new int[totalMasks];
+    int[] maskCount = new int[totalMasks];
+
+    char[][] patterns = new char[n][m];
+    int[] masks = new int[n];
+
+    for (int i = 0; i < n; i++) {
+      String line = br.readLine().trim();
+      int mask = 0;
+      for (int j = 0; j < m; j++) {
+        patterns[i][j] = line.charAt(j);
+        if (patterns[i][j] != '?')
+          mask |= (1 << j);
+      }
+      masks[i] = mask;
+      maskCount[mask]++;
+    }
+
+    for (int mask = 0; mask < totalMasks; mask++) {
+      maskPatterns[mask] = new int[maskCount[mask]];
+    }
+
+    for (int i = 0; i < n; i++) {
+      int mask = masks[i];
+      int code = encode(patterns[i], mask);
+      maskPatterns[mask][maskSize[mask]++] = code;
+    }
+
+    long answer = 0;
+
+    int[] projA = new int[n];
+    int[] projB = new int[n];
+
+    for (int a = 0; a < totalMasks; a++) {
+      if (maskPatterns[a].length == 0)
+        continue;
+      for (int b = a; b < totalMasks; b++) {
+        if (maskPatterns[b].length == 0)
+          continue;
+
+        int conflict = a & b;
+
+        if (a == b) {
+          int sz = maskPatterns[a].length;
+          for (int i = 0; i < sz; i++) {
+            projA[i] = reproject(maskPatterns[a][i], a, conflict);
+          }
+          Arrays.sort(projA, 0, sz);
+          int i = 0;
+          while (i < sz) {
+            int j = i + 1;
+            while (j < sz && projA[j] == projA[i])
+              j++;
+            long cnt = j - i;
+            answer += cnt * (cnt - 1) / 2;
+            i = j;
+          }
+        } else {
+          int sza = maskPatterns[a].length;
+          int szb = maskPatterns[b].length;
+          for (int i = 0; i < sza; i++)
+            projA[i] = reproject(maskPatterns[a][i], a, conflict);
+          for (int i = 0; i < szb; i++)
+            projB[i] = reproject(maskPatterns[b][i], b, conflict);
+          Arrays.sort(projA, 0, sza);
+          Arrays.sort(projB, 0, szb);
+          int i = 0, j = 0;
+          while (i < sza && j < szb) {
+            if (projA[i] == projB[j]) {
+              int cntA = 1, cntB = 1;
+              while (i + cntA < sza && projA[i + cntA] == projA[i])
+                cntA++;
+              while (j + cntB < szb && projB[j + cntB] == projB[j])
+                cntB++;
+              answer += (long) cntA * cntB;
+              i += cntA;
+              j += cntB;
+            } else if (projA[i] < projB[j])
+              i++;
+            else
+              j++;
+          }
+        }
+      }
+    }
+
+    System.out.println(answer);
+  }
+
+  static int encode(char[] pattern, int mask) {
+    int code = 0;
+    for (int i = 0; i < m; i++) {
+      if ((mask & (1 << i)) != 0) {
+        code = code * 27 + (pattern[i] - 'a' + 1);
+      }
+    }
+    return code;
+  }
+
+  static int reproject(int code, int srcMask, int targetMask) {
+    int[] vals = new int[6];
+    int idx = 0;
+    for (int i = 0; i < 6; i++) {
+      if ((srcMask & (1 << i)) != 0) {
+        vals[idx++] = code % 27;
+        code /= 27;
+      }
+    }
+    int result = 0, mul = 1;
+    int[] srcBits = new int[6];
+    int srcCount = 0;
+    for (int i = 0; i < 6; i++) {
+      if ((srcMask & (1 << i)) != 0)
+        srcBits[srcCount++] = i;
+    }
+    for (int k = 0; k < srcCount; k++) {
+      if ((targetMask & (1 << srcBits[k])) != 0) {
+        result += vals[srcCount - 1 - k] * mul;
+        mul *= 27;
+      }
+    }
+    return result;
+  }
+}

1/D/test1.in

@@ -0,0 +1,4 @@
+3 3
+??b
+c??
+c?c

1/D/test2.in

@@ -0,0 +1,5 @@
+4 6
+ab??c?
+??kll?
+a?k??c
+?bcd??

1/D/test3.in

@@ -0,0 +1,6 @@
+5 2
+??
+b?
+c?
+?g
+cg