畅通工程(并查集)

还是寻求father[i]=i代表几个集合,还有初始化MAXN不能有等于,Make_seth函数再次忘记写了

#include<stdio.h>

const int MAXN=1010;

int father[MAXN],rank[MAXN];

void Make_set()
{
    for(int i=1;i<MAXN;i++)
    {
        father[i]=i;
        rank[i]=0;
    }
}

int Find(int x)
{
    int r=x;
    while(r!=father[r])
    {
        r=father[r];
    }
    if(r!=x) father[x]=r;
    return father[x];
}

void Union(int x,int y)
{
    if(x==y) return ;
    if(rank[x]>rank[y])
    {
        father[y]=x;
    }
    else
    {
        if(rank[x]==rank[y])
        {
            rank[y]++;
        }
        father[x]=y;
    }
}

int main()
{
    int n,m,i,a,b;
    while(scanf("%d",&n))
    {
        if(n==0) break;
        scanf("%d",&m);
        Make_set();
        for(i=0;i<m;i++)
        {
            scanf("%d%d",&a,&b);
            int x=Find(a);
            int y=Find(b);
            Union(x,y);
        }
        int total=0;
        for(i=1;i<=n;i++)
        {
           // printf("%d\n",father[i]);
            if(father[i]==i) total++;
        }
        printf("%d\n",total-1);
    }
    return 0;
}
posted @ 2012-08-07 10:57  calmound  阅读(192)  评论(0编辑  收藏  举报