求最小生成树_普里姆算法(Prim)

package com.test;

import java.util.Arrays;

// 求最小生成树----普里姆算法(Prim)
public class MiniSpanTreePrim {
	public static void main(String[] args) {
		// 构造最小生成树
		int vertexNumber = 9;// 定点数
		int arr[][] = new int[vertexNumber][vertexNumber];// 图的邻接矩阵
		for (int i = 0; i < vertexNumber; i++) {
			for (int j = 0; j < vertexNumber; j++) {
				if (i == j) {
					arr[i][j] = 0;
				} else {
					// arr[i][j] = Integer.MAX_VALUE;
					arr[i][j] = 65535;
				}
			}
		}
		arr[0][1] = 10;
		arr[0][5] = 11;
		arr[1][0] = 10;
		arr[1][2] = 18;
		arr[1][6] = 16;
		arr[1][8] = 12;
		arr[2][1] = 18;
		arr[2][3] = 22;
		arr[2][8] = 8;
		arr[3][2] = 22;
		arr[3][8] = 21;
		arr[3][6] = 24;
		arr[3][7] = 16;
		arr[3][4] = 20;
		arr[4][3] = 20;
		arr[4][7] = 7;
		arr[4][5] = 26;
		arr[5][0] = 11;
		arr[5][6] = 17;
		arr[5][4] = 26;
		arr[6][1] = 16;
		arr[6][5] = 17;
		arr[6][3] = 24;
		arr[6][7] = 19;
		arr[7][6] = 19;
		arr[7][3] = 16;
		arr[7][4] = 7;
		arr[8][1] = 12;
		arr[8][2] = 8;
		arr[8][3] = 21;
		System.out.println("图的邻接矩阵：");
		for (int i = 0; i < vertexNumber; i++) {
			for (int j = 0; j < vertexNumber; j++) {
				System.out.print(arr[i][j] + "\t");
			}
			System.out.println();
		}
		System.out.println("------------------------");

		// 开始生成最小树--prim(默认从v0开始)
		int[] vertexIndex = new int[vertexNumber];// 保存顶点索引
		int[] minWeightArr = new int[vertexNumber];// 保存相关顶点间的权值
		// 把第一行权值存入minWeightArr
		for (int i = 0; i < vertexNumber; i++) {
			minWeightArr[i] = arr[0][i];// 将于v0顶点相关的顶点存入minWeight
		}

		for (int i = 1; i < vertexNumber; i++) {
			// int minWeight = Integer.MAX_VALUE;// 最小权值
			int minWeight = 65535;// 最小权值
			int j = 0;// 顶点下标循环变量
			int k = 0;// 最小权值顶点下标
			// 找出minWeightArr中最小的权值
			while (j < vertexNumber) {
				if (minWeightArr[j] != 0 && minWeightArr[j] < minWeight) {
					minWeight = minWeightArr[j];
					k = j;
				}
				j++;
			}

			System.out.print(Arrays.toString(vertexIndex) + "\t");
			System.out.print(Arrays.toString(minWeightArr) + "\t");
			System.out.println("( " + vertexIndex[k] + " , " + k + " ) ");

			minWeightArr[k] = 0;
			// 找出第k行中，较小的权值存入minWeightArr
			for (j = 1; j < vertexNumber; j++) {
				if (minWeightArr[j] != 0 && arr[k][j] < minWeightArr[j]) {
					minWeightArr[j] = arr[k][j];
					vertexIndex[j] = k;
				}
			}
		}

	}
}

输出结果：

图的邻接矩阵：
0	10	65535	65535	65535	11	65535	65535	65535	
10	0	18	65535	65535	65535	16	65535	12	
65535	18	0	22	65535	65535	65535	65535	8	
65535	65535	22	0	20	65535	24	16	21	
65535	65535	65535	20	0	26	65535	7	65535	
11	65535	65535	65535	26	0	17	65535	65535	
65535	16	65535	24	65535	17	0	19	65535	
65535	65535	65535	16	7	65535	19	0	65535	
65535	12	8	21	65535	65535	65535	65535	0	
------------------------
[0, 0, 0, 0, 0, 0, 0, 0, 0]	[0, 10, 65535, 65535, 65535, 11, 65535, 65535, 65535]	( 0 , 1 ) 
[0, 0, 1, 0, 0, 0, 1, 0, 1]	[0, 0, 18, 65535, 65535, 11, 16, 65535, 12]	( 0 , 5 ) 
[0, 0, 1, 0, 5, 0, 1, 0, 1]	[0, 0, 18, 65535, 26, 0, 16, 65535, 12]	( 1 , 8 ) 
[0, 0, 8, 8, 5, 0, 1, 0, 1]	[0, 0, 8, 21, 26, 0, 16, 65535, 0]	( 8 , 2 ) 
[0, 0, 8, 8, 5, 0, 1, 0, 1]	[0, 0, 0, 21, 26, 0, 16, 65535, 0]	( 1 , 6 ) 
[0, 0, 8, 8, 5, 0, 1, 6, 1]	[0, 0, 0, 21, 26, 0, 0, 19, 0]	( 6 , 7 ) 
[0, 0, 8, 7, 7, 0, 1, 6, 1]	[0, 0, 0, 16, 7, 0, 0, 0, 0]	( 7 , 4 ) 
[0, 0, 8, 7, 7, 0, 1, 6, 1]	[0, 0, 0, 16, 0, 0, 0, 0, 0]	( 7 , 3 )