最小生成树Prim算法实现

来源：互联网发布：数据分析经典案例分享编辑：程序博客网时间：2024/06/03 23:43

师姐毕设论文中，重点利用最小生成树实现立体匹配，最小生成树本身为常用的算法，故抽出时间以C++将其实现。

//============================================================================// Name        : MST.cpp// Author      : Julie// Version     : 0.0.1// Copyright   : Julie@2014.10.19// Description : To Generate the MST withPrim algorithm//============================================================================#include <iostream>#include <memory.h>#include <algorithm>using namespace std;#define N 7#define M 7#define inf 10000typedef struct node{    int matrix[N][M];      //邻接矩阵    int n;                 //顶点数    int e;                 //边数}MGraph1;void MST(MGraph1 Mtest){bool  known[N];memset(known, 0, sizeof(known));int dist[N];for (int i = 1; i<=Mtest.n; i++)dist[i] = inf;int  pv[N];memset(pv, 0, sizeof(pv));known[0]=true;dist[0]=inf;pv[0]=0;int n_now=0;for (int j = 1; j<Mtest.n; j++){int number, dist_tmp;number= n_now;dist_tmp=inf;for (int i = 1; i<Mtest.n; i++){if (!known[i]){//更新dist值：未归类的点+与当前点有临接+小于原来dist值if (Mtest.matrix[i][n_now]>0 && dist[i]>Mtest.matrix[i][n_now]){dist[i] = Mtest.matrix[i][n_now];pv[i]=n_now;}//找到最小dist的值与坐标if (dist_tmp>dist[i]){dist_tmp=dist[i];number= i;}}}cout<<number<<" "<<pv[number]<<":"<<dist_tmp<<endl;n_now=number;known[n_now]=true;}}int main(){MGraph1 MGraph;MGraph.n = 7;MGraph.e = 12;int n1,n2,e;for (int i = 0; i < MGraph.n; i++){for (int j = 0; j < MGraph.n; j++)MGraph.matrix[i][j] = -inf;}for (int i = 0; i < MGraph.e; i++){cin>>n1>>n2;cin>>MGraph.matrix[n1][n2];MGraph.matrix[n2][n1] = MGraph.matrix[n1][n2];}MST(MGraph);return 0;}

附上一组测试数据及结果：

test：

0 1 2
0 2 4
0 3 1
1 3 3
1 4 10
3 4 7
2 3 2
2 5 5
3 5 8
5 6 1
3 6 4
4 6 6

result：

3 0:1
1 0:2
2 3:2
6 3:4
5 6:1
4 6:6

0 0