FordFulkerson.java

import java.util.Arrays;

class MaxFlowFordFulkerson {
  static int[][] capacity = { { 0, 3, 2 }, { 0, 0, 2 }, { 0, 0, 0 } };

  public static int maxFlow(int s, int t) {
    for (int flow = 0;;) {
      int df = findPath(new boolean[capacity.length], s, t, Integer.MAX_VALUE);
      if (df == 0) {
        return flow;
      }
      flow += df;
    }
  }

  static int findPath(boolean[] vis, int u, int t, int f) {
    if (u == t) {
      return f;
    }

    vis[u] = true;
    for (int v = 0; v < vis.length; v++) {
      if (!vis[v] && capacity[u][v] > 0) {
        int df = findPath(vis, v, t, Math.min(f, capacity[u][v]));
        if (df > 0) {
          capacity[u][v] -= df;
          capacity[v][u] += df;
          return df;
        }
      }
    }

    return 0;
  }

  public static void main(String[] args) {
    System.out.println(maxFlow(0, 2));
    System.out.println(Arrays.deepToString(capacity));
  }
}