AOJ 1163 Cards
http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1163
GCD + 二部マッチング
import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.ArrayDeque; import java.util.ArrayList; import java.util.Arrays; import java.util.NoSuchElementException; public class Main { private static long gcd(long a, long b) { return b == 0 ? a : gcd(b, a % b); } private void solve(FastScanner in, PrintWriter out) { while (true) { int m = in.nextInt(); int n = in.nextInt(); if (m == 0 && n == 0) { break; } int[] b = in.nextIntArray(m); int[] r = in.nextIntArray(n); Dinitz dinitz = new Dinitz(n + m + 2); int source = n + m; int sink = source + 1; for (int i = 0; i < m; i++) { for (int j = 0; j < n; j++) { if (gcd(b[i], r[j]) > 1) { dinitz.addEdge(i, j + m, 1); } } } for (int i = 0; i < m; i++) { dinitz.addEdge(source, i, 1); } for (int i = 0; i < n; i++) { dinitz.addEdge(i + m, sink, 1); } out.println(dinitz.maxFlow(source, sink)); } } class Dinitz { class Edge { int to, rev; long cap; Edge(int to, long cap, int rev) { this.to = to; this.cap = cap; this.rev = rev; } } private ArrayDeque<Integer> deque = new ArrayDeque<>(); private ArrayList<ArrayList<Edge>> g; private int[] level; private int[] iter; Dinitz(int V) { g = new ArrayList<>(V); for (int i = 0; i < V; i++) { g.add(new ArrayList<>()); } level = new int[V]; iter = new int[V]; } void addEdge(int from, int to, long cap) { g.get(from).add(new Edge(to, cap, g.get(to).size())); g.get(to).add(new Edge(from, 0, g.get(from).size() - 1)); } private long dfs(int v, int t, long f) { if (v == t) { return f; } for (; iter[v] < g.get(v).size(); iter[v]++) { Edge e = g.get(v).get(iter[v]); if (e.cap > 0 && level[v] < level[e.to]) { long d = dfs(e.to, t, Math.min(f, e.cap)); if (d > 0) { e.cap -= d; g.get(e.to).get(e.rev).cap += d; return d; } } } return 0; } private void bfs(int s) { Arrays.fill(level, -1); level[s] = 0; deque.add(s); while (!deque.isEmpty()) { int v = deque.poll(); for (Edge e : g.get(v)) { if (e.cap > 0 && level[e.to] < 0) { level[e.to] = level[v] + 1; deque.add(e.to); } } } } long maxFlow(int s, int t) { long flow = 0; for (; ; ) { bfs(s); if (level[t] < 0) { return flow; } Arrays.fill(iter, 0); long f; while ((f = dfs(s, t, Long.MAX_VALUE)) > 0) { flow += f; } } } } public static void main(String[] args) { PrintWriter out = new PrintWriter(System.out); new Main().solve(new FastScanner(), 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; } public long[] nextLongArray(int n) { long[] array = new long[n]; for (int i = 0; i < n; i++) { array[i] = nextLong(); } return array; } public String[] nextStringArray(int n) { String[] array = new String[n]; for (int i = 0; i < n; i++) { array[i] = next(); } return array; } public char[][] nextCharMap(int n) { char[][] array = new char[n][]; for (int i = 0; i < n; i++) { array[i] = next().toCharArray(); } return array; } public int[][] nextIntMap(int n, int m) { int[][] map = new int[n][]; for (int i = 0; i < n; i++) { map[i] = nextIntArray(m); } return map; } } }