克鲁斯卡尔算法

设N=(V,{E})是连通网

      1)令最小生成树的初始状态为只有n个顶点而无边的非连通图T=(V, {})，图中每个顶点自成一个连通分量；

      2)在E中选择代价最小的边，若该边依附的顶点落在T中不同的连通分量上，则将此边加入到T中，否则舍去此边而选择下一条代价最小的边；

      3)反复执行第2)步，直至T中所有顶点都在同一连通分量上为止。

        则T=(V, {TE})为N的最小生成树。

#include <cstdio>#include <cstdlib>#include <algorithm>#define MAX 20using namespace std;typedef struct{int data;int jihe;}VexNode;typedef struct{int vexh,vext;int weight;}EdgeNode;int cmp(EdgeNode A, EdgeNode B){return A.weight < B.weight;}void Kruskal(EdgeNode e[], int vexnum, int arcnum){VexNode vex[MAX];int i;for(i = 1; i <= vexnum; i ++){vex[i - 1].data = vex[i - 1].jihe = i;}int m1,m2,n1,n2,j,k = 1;i = 0;printf("\n=====华丽分割线=====\n");while(k < vexnum){m1 = e[i].vexh;m2 = e[i].vext;n1 = vex[m1- 1].jihe;n2 = vex[m2 - 1].jihe;if(n1 != n2){printf("%d %d %d\n",m1,m2,e[i].weight);k ++;for(j = 0; j < vexnum; j ++){if(n2 == vex[j].jihe)vex[j].jihe = n1;}}i ++;}}int main(){EdgeNode e[MAX];int vexnum,arcnum;scanf("%d%d",&vexnum,&arcnum);for(int i = 0; i < arcnum; i ++){scanf("%d%d%d",&e[i].vexh,&e[i].vext,&e[i].weight);}sort(e,e+arcnum,cmp);Kruskal(e,vexnum,arcnum);return 0;}