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FordFulkerson.java
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70 lines (62 loc) · 1.92 KB
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package DynamicProgramming;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Vector;
public class FordFulkerson {
static final int INF = 987654321;
// edges
static int V;
static int[][] capacity, flow;
public static void main(String[] args) {
System.out.println("V : 6");
V = 6;
capacity = new int[V][V];
capacity[0][1] = 12;
capacity[0][3] = 13;
capacity[1][2] = 10;
capacity[2][3] = 13;
capacity[2][4] = 3;
capacity[2][5] = 15;
capacity[3][2] = 7;
capacity[3][4] = 15;
capacity[4][5] = 17;
System.out.println("Max capacity in networkFlow : " + networkFlow(0, 5));
}
private static int networkFlow(int source, int sink) {
flow = new int[V][V];
int totalFlow = 0;
while (true) {
Vector<Integer> parent = new Vector<>(V);
for (int i = 0; i < V; i++) parent.add(-1);
Queue<Integer> q = new LinkedList<>();
parent.set(source, source);
q.add(source);
while (!q.isEmpty() && parent.get(sink) == -1) {
int here = q.peek();
q.poll();
for (int there = 0; there < V; ++there)
if (capacity[here][there] - flow[here][there] > 0 && parent.get(there) == -1) {
q.add(there);
parent.set(there, here);
}
}
if (parent.get(sink) == -1) break;
int amount = INF;
String printer = "path : ";
StringBuilder sb = new StringBuilder();
for (int p = sink; p != source; p = parent.get(p)) {
amount = Math.min(capacity[parent.get(p)][p] - flow[parent.get(p)][p], amount);
sb.append(p + "-");
}
sb.append(source);
for (int p = sink; p != source; p = parent.get(p)) {
flow[parent.get(p)][p] += amount;
flow[p][parent.get(p)] -= amount;
}
totalFlow += amount;
printer += sb.reverse() + " / max flow : " + totalFlow;
System.out.println(printer);
}
return totalFlow;
}
}