poj 1988 Cube Stacking

purplest — Tue, 06 Sep 2011 09:50:00 GMT

并查集用的很巧妙

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

int parent[30010], count[30010];

void init()
{
    memset(parent, -1, sizeof(parent));
    memset(count, 0, sizeof(count));
}

int find(int i)
{
    if ( 0 > parent[i] )
        return i;
    int t= parent[i];
    parent[i]= find(parent[i]);
    count[i]+=count[t];
    return parent[i];
}

void unionset(int a, int b)
{
    a= find(a);
    b= find(b);
    if ( a == b ) return;
    int t= parent[a];
    parent[a]= b;
    count[a]= count[a]-parent[b];
    parent[b]+=t;
}

int main()
{
    int n, a, b;
    char ch;
    scanf("%d", &n);
    init();
    while ( n-- )
    {
        scanf("%*c%c", &ch);
        if ( 'M' == ch )
        {
            scanf("%d%d", &a, &b);
            unionset(a, b);
        }
        if ( 'C' == ch )
        {
            scanf("%d", &a);
            find(a);
            printf("%d\n", count[a]);
        }
    }
    return 0;
}

purplest 2011-09-06 17:50 发表评论

C++博客-purplest-随笔分类-并查集

poj 1988 Cube Stacking