没日一算法 （网络最大流）3.12

import java.util.*;

/**

*

* @author Administrator dai liyun

* @since 2010.3.11 求网络最大流

*/

public class MaxFlow {

private int[][] edges;/*

* = { { 0, 1, 1, 0, 0 }, { 0, 0, 0, 1, 1 }, { 0, 0, 0,

* 1, 0 }, { 0, 0, 0, 0, 1 }, { 0, 0, 0, 0, 0 } };

*/

private int[][] flows;/* = edges; */

private boolean[] label;

final int length;

public MaxFlow() {

System.out.println("enter the graphics size ");

Scanner cin = new Scanner(System.in);

length = cin.nextInt();

edges = new int[length][length];

flows = new int[length][length];

label = new boolean[length];

System.out.println("enter Adjacency matrix");

for (int i = 0; i < length; i++) {

label[i] = false;

for (int j = 0; j < length; j++) {

edges[i][j] = cin.nextInt();

flows[i][j] = edges[i][j];

}

}

search();

for (int i = 0; i < length; i++) {

for (int j = 0; j < length; j++) {

if (flows[i][j] > 0) {

flows[i][j] -= edges[i][j];

}

}

}

System.out.println("search end the result is:");

for (int i = 0; i < length; i++) {

System.out.println();

for (int j = 0; j < length; j++) {

System.out.print(" " + flows[i][j]);

}

}

}

public void search() {

int minLabelIndex = 0;

int minMax = 0;

boolean state = true;

while (minLabelIndex < length - 1) {

int[] path = new int[length];

int pathIndex = 0, searchV = minLabelIndex;

for (int i = 0; i < length; i++) {

path[i] = -1;

}

minMax = Integer.MAX_VALUE;

searchV = minLabelIndex;

path[pathIndex++] = minLabelIndex;

while (searchV < length - 1) {

int t = 0;

int next = 0;

for (int h = 0; h < length; h++) {

if (canChoose(searchV, h, t, path)) {

t = edges[searchV][h];

next = h;

}

}

minMax = (minMax < t) ? minMax : t;

if (minMax == 0) {

label[searchV] = true;

for (int i = 0; i < length; i++) {

if (!label[i]) {

minLabelIndex = i;

break;

}

}

state = false;

break;

}

searchV = next;

path[pathIndex++] = searchV;

}

if (state) {

int i = 0;

while (i < length - 1 && path[i + 1] > -1) {

int xlabel = path[i];

int ylabel = path[i + 1];

edges[xlabel][ylabel] -= minMax;

edges[ylabel][xlabel] += minMax;

i++;

}

} else

state = true;

}

}

private boolean canChoose(int n, int h, int t, int[] temp) {

if (!label[h] && edges
[h] >= t && h != n && noLoop(temp, h))

return true;

return false;

}

private boolean noLoop(int[] temp, int x) {

int i = 0;

while (temp[i] != -1) {

if (temp[i] == x)

return false;

i++;

}

return true;

}

public static void main(String[] args) {

MaxFlow f = new MaxFlow();

}

}