【最小生成树】

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define N 100
int vexs[N], arcs[N][N];
int vexNum, arcNum;
int INF = 999;
int sum;

void Prim(int v)
{
    int s[N], i, j, w[N], u, min;
    memset(s, 0, sizeof(s));
    memset(s, 0, sizeof(w));
    s[v] = 1;
    for(i = 1; i <= vexNum; i++)
        w[i] = arcs[v][i];
    for(i = 2; i <= vexNum; i++)
    {
        min = INF;
        for(j = 1; j <= vexNum; j++)
        {
            if(!s[j] && w[j] < min)
            {
                min = w[j];
                u = j;
            }
        }
         sum += min;
        s[u] = 1;
        for(j = 1; j <= vexNum; j++)
            if(!s[j] && arcs[u][j] < w[j])
                w[j] = arcs[u][j];
    }
}

void Kruskal()
{
    int i, j, k, s1, s2, num, vset[N], v1, v2;
    struct edgeType
    {
        int u, v, w;
    }t, *edge;
    edge = (struct edgeType *)malloc(arcNum * sizeof(struct edgeType));
    k = 1;
    for(i = 1; i <= vexNum; i++)
        for(j = 1; j <= vexNum; j++)
            if(arcs[i][j] != INF)
            {
                edge[k].u = i;
                edge[k].v = j;
                edge[k].w = arcs[i][j];
                k++;
            }
    for(i = 2; i <= k; i++)
        for(j = 1; j <= k - i; j++)
            if(edge[j].w > edge[j + 1].w)
            {
                t = edge[j];
                edge[j] = edge[j + 1];
                edge[j + 1] = t;
            }
    for(i = 1; i <= vexNum; i++)
        vset[i] = i;
    num = 2; j = 1;
    while(num <= vexNum)
    {
        v1 = edge[j].u;
        v2 = edge[j].v;
        s1 = vset[v1];
        s2 = vset[v2];
        if(s1 != s2)
        {
            sum += edge[j].w;//
            num++;
            for(i = 1; i <= vexNum; i++)
                if(vset[i] == s2)
                    vset[i] = s1;
        }
        j++;
    }
}

int main(int argc, char *argv[])
{
    int i, j, v1, v2;
    scanf("%d%d", &vexNum, &arcNum);
    for(i = 1; i <= vexNum; i++)
        scanf("%d", &vexs[i]);
    for(i = 1; i <= vexNum; i++)
        for(j = 1; j <= vexNum; j++)
            arcs[i][j] = INF;
    for(i = 1; i <= arcNum; i++)
    {
        scanf("%d%d", &v1, &v2);
        scanf("%d", &arcs[v1][v2]);
        arcs[v2][v1] = arcs[v1][v2];
    }
    sum = 0;
    //Prim(1);
    Kruskal();
    printf("%d\n", sum);
    return 0;
}
/*
5 7
1 2 3 4 5
1 2 2
2 4 2
4 5 4
3 4 2
2 5 1
3 5 3
1 3 1

6
*/