package com.atguigu.prim;import java.util.Arrays;public class PrimAlgorithm {public static void mainString[] args) {//测试看看图是否创建okchar[] data = new char[]{'A','B','C','D','E','F','G'};int verxs = data.length;//邻接矩阵的关系使用二维数组表示,10000这个大数，表示两个点不联通int [][]weight=new int[][]{{10000,5,7,10000,10000,10000,2},{5,10000,10000,9,10000,10000,3},{7,10000,10000,10000,8,10000,10000},{10000,9,10000,10000,10000,4,10000},{10000,10000,8,10000,10000,5,4},{10000,10000,10000,4,5,10000,6},{2,3,10000,10000,4,6,10000},};//创建MGraph对象MGraph graph = new MGraphverxs);//创建一个MinTree对象MinTree minTree = new MinTree);minTree.createGraphgraph, verxs, data, weight);//输出minTree.showGraphgraph);//测试普利姆算法minTree.primgraph, 1);// }}//创建最小生成树->村庄的图
class MinTree {//创建图的邻接矩阵/*** * @param graph 图对象* @param verxs 图对应的顶点个数* @param data 图的各个顶点的值* @param weight 图的邻接矩阵*/public void createGraphMGraph graph, int verxs, char data[], int[][] weight) {int i, j;fori = 0; i < verxs; i++) {//顶点graph.data[i] = data[i];forj = 0; j < verxs; j++) {graph.weight[i][j] = weight[i][j];}}}//显示图的邻接矩阵public void showGraphMGraph graph) {forint[] link: graph.weight) {System.out.printlnArrays.toStringlink));}}//编写prim算法，得到最小生成树/*** * @param graph 图* @param v 表示从图的第几个顶点开始生成'A'->0 'B'->1...*/public void primMGraph graph, int v) {//visited[] 标记结点顶点)是否被访问过int visited[] = new int[graph.verxs];//visited[] 默认元素的值都是0, 表示没有访问过
// forint i =0; i <graph.verxs; i++) {
// visited[i] = 0;
// }//把当前这个结点标记为已访问visited[v] = 1;//h1 和 h2 记录两个顶点的下标int h1 = -1;int h2 = -1;int minWeight = 10000; //将 minWeight 初始成一个大数，后面在遍历过程中，会被替换forint k = 1; k < graph.verxs; k++) {//因为有 graph.verxs顶点，普利姆算法结束后，有 graph.verxs-1边//这个是确定每一次生成的子图 ，和哪个结点的距离最近forint i = 0; i < graph.verxs; i++) {// i结点表示被访问过的结点forint j = 0; j< graph.verxs;j++) {//j结点表示还没有访问过的结点ifvisited[i] == 1 && visited[j] == 0 && graph.weight[i][j] < minWeight) {//替换minWeight寻找已经访问过的结点和未访问过的结点间的权值最小的边)minWeight = graph.weight[i][j];h1 = i;h2 = j;}}}//找到一条边是最小System.out.println"边<" + graph.data[h1] + "," + graph.data[h2] + "> 权值:" + minWeight);//将当前这个结点标记为已经访问visited[h2] = 1;//minWeight 重新设置为最大值 10000minWeight = 10000;}}
}class MGraph {int verxs; //表示图的节点个数char[] data;//存放结点数据int[][] weight; //存放边，就是我们的邻接矩阵public MGraphint verxs) {this.verxs = verxs;data = new char[verxs];weight = new int[verxs][verxs];}
}