MaxMatching.java

package hu.sztaki.ilab.longneck.util;

import java.util.*;

public class MaxMatching {

    static boolean findPath(int u1, boolean[][] d, int[] matching, boolean[] vis) {
        vis[u1] = true;
        for (int v = 0; v < matching.length; ++v) {
            int u2 = matching[v];
            if (d[u1][v] && (u2 == -1 || !vis[u2] && findPath(u2, d, matching, vis))) {
                matching[v] = u1;
                return true;
            }
        }
        return false;
    }

    public static int maxMatching(boolean[][] d) {
        int n1 = d.length;
        int n2 = n1 == 0 ? 0 : d[0].length;
        int[] matching = new int[n2];
        Arrays.fill(matching, -1);
        int matches = 0;
        for (int u = 0; u < n1; u++)
            if (findPath(u, d, matching, new boolean[n1]))
                ++matches;
        return matches;
    }

}