hust 1102 Constructing Roads

#include<iostream>
#include<cstdio>
#include<vector>
#include<algorithm>
using namespace std;
const int MAX=1000000;
struct node
{
    int left,right,cost;
}road[MAX];

bool cmp(node x,node y){return x.cost<y.cost;}

int p[MAX],m,n;

int find(int x){return x==p[x]? x:p[x]=find(p[x]);}

int kruskal()
{
    int ans=0;
    for (int i=0;i<=n;i++) p[i]=i;
    for (int i=0;i<m;i++)
    {
        int x=find(road[i].left);
        int y=find(road[i].right);
        if(x!=y)
        {
            ans+=road[i].cost;
            p[x]=y;
        }
    }
    return ans;
}

int main()
{
    int x,y,c,G[101][101],q;
    while(scanf("%d",&n)!=EOF)
    {
        for (int i=1;i<=n;i++)
        for (int j=1;j<=n;j++)
        scanf("%d",&G[i][j]);
        scanf("%d",&q);
        for (int i=0;i<q;i++)
        {
            scanf("%d%d",&x,&y);
            G[x][y]=0;
        }
        m=0;
        for (int i=1;i<=n;i++)
        for (int j=1;j<=n;j++)
        {
            if (i!=j)
            {
                road[m].left=i;
                road[m].right=j;
                road[m].cost=G[i][j];
                m++;
            }
        }
        sort(road,road+m,cmp);
        printf("%d\n",kruskal());
    }
    return 0;
}