天下一プログラマーコンテスト2014予選A C - 天下一文字列集合
解法
bitDP
コード
package atcoder.tenka12014quala; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintWriter; import java.util.NoSuchElementException; public class C { private static class Task { void solve(FastScanner in, PrintWriter out) { int N = in.nextInt(); int M = in.nextInt(); char[][] str = new char[N][]; for (int i = 0; i < N; i++) str[i] = in.next().toCharArray(); boolean[][] map = new boolean[N][N]; for (int i = 0; i < N; i++) map[i][i] = true; for (int i = 0; i < N; i++) { for (int j = i + 1; j < N; j++) { boolean ok = true; for (int m = 0; m < M; m++) { if (str[i][m] != str[j][m] && str[i][m] != '*' && str[j][m] != '*') { ok = false; break; } } if (ok) { map[i][j] = true; map[j][i] = true; } } } int[] dp = new int[1 << N]; for (int mask = 0; mask < (1 << N); mask++) { boolean ok = true; check: for (int i = 0; i < N; i++) { if ((mask & (1 << i)) == 0) continue; for (int j = i + 1; j < N; j++) { if ((mask & (1 << j)) == 0) continue; if (!map[i][j]) { ok = false; break check; } } } if (ok) { dp[mask] = 1; continue; } int min = Integer.bitCount(mask); for (int subMask = 1; subMask < mask; subMask++) { if ((subMask & mask) != subMask) continue; min = Math.min(min, dp[subMask] + dp[mask - subMask]); } dp[mask] = min; } out.println(dp[(1 << N) - 1]); } } // Template public static void main(String[] args) { OutputStream outputStream = System.out; FastScanner in = new FastScanner(); PrintWriter out = new PrintWriter(outputStream); Task solver = new Task(); solver.solve(in, out); out.close(); } private static class FastScanner { private final InputStream in = System.in; private final byte[] buffer = new byte[1024]; private int ptr = 0; private int bufferLength = 0; private boolean hasNextByte() { if (ptr < bufferLength) { return true; } else { ptr = 0; try { bufferLength = in.read(buffer); } catch (IOException e) { e.printStackTrace(); } if (bufferLength <= 0) { return false; } } return true; } private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1; } private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126; } private void skipUnprintable() { while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; } boolean hasNext() { skipUnprintable(); return hasNextByte(); } public String next() { if (!hasNext()) throw new NoSuchElementException(); StringBuilder sb = new StringBuilder(); int b = readByte(); while (isPrintableChar(b)) { sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } long nextLong() { if (!hasNext()) throw new NoSuchElementException(); long n = 0; boolean minus = false; int b = readByte(); if (b == '-') { minus = true; b = readByte(); } if (b < '0' || '9' < b) { throw new NumberFormatException(); } while (true) { if ('0' <= b && b <= '9') { n *= 10; n += b - '0'; } else if (b == -1 || !isPrintableChar(b)) { return minus ? -n : n; } else { throw new NumberFormatException(); } b = readByte(); } } double nextDouble() { return Double.parseDouble(next()); } double[] nextDoubleArray(int n) { double[] array = new double[n]; for (int i = 0; i < n; i++) { array[i] = nextDouble(); } return array; } double[][] nextDoubleMap(int n, int m) { double[][] map = new double[n][]; for (int i = 0; i < n; i++) { map[i] = nextDoubleArray(m); } return map; } public int nextInt() { return (int) nextLong(); } public int[] nextIntArray(int n) { int[] array = new int[n]; for (int i = 0; i < n; i++) { array[i] = nextInt(); } return array; } } }