POJ1611

标签：lists   init   div   spi   break   find   rank   uniq   sum   

Description

Input

Output

Sample Input

100 4
2 1 2
5 10 13 11 12 14
2 0 1
2 99 2
200 2
1 5
5 1 2 3 4 5
1 0
0 0

Sample Output

4
1
1

提交一直出现Wrong Answer，主要代码出错在union_set方法。

之前

void union_set(int x,int y){
	x = find_set(x);
	y = find_set(y);
	if(rank[x] >  rank[y]){
		pa[y] = x;
		count[x] += count[y];
	}
	else{
		pa[x] = y;
		if(rank[x] == rank[y]){
			rank[y]++;
		}
		count[y] += count[x];
	}

}

修改为

void union_set(int x,int y){
	x = find_set(x);
	y = find_set(y);
	if(x==y) return;	
	if(rank[x] > rank[y])
	{
		pa[y] = x;
		count[x] += count[y];
		rank[x]++;
	}
	else
	{
		pa[x] = y;
		rank[y]++;
		count[y] += count[x];
	}
}

通过了

#include <cstdio>

const int MAXN = 30001;
int pa[MAXN];
int rank[MAXN];
int count[MAXN];

void make_set(int x){
	pa[x] = x;
	rank[x] = 0;
	count[x] = 1;
}

int find_set(int x){
	if(x != pa[x]){
		pa[x] = find_set(pa[x]);
	}
	return pa[x];
}

void union_set(int x,int y){
	x = find_set(x);
	y = find_set(y);
	if(x==y) return;	
	if(rank[x] > rank[y])
	{
		pa[y] = x;
		count[x] += count[y];
		rank[x]++;
	}
	else
	{
		pa[x] = y;
		rank[y]++;
		count[y] += count[x];
	}

}


int main(void){
	int n,m;
	while(1){
		int i;
		scanf("%d%d",&n,&m);
		if(0==n && 0==m){
			break;
		}
		for(i=0;i<n;i++){
			make_set(i);
		}
		for(i=0;i<m;i++){
			int k,first,j;
			scanf("%d%d",&k,&first);
			for(j=1;j<k;j++){
				int next;
				scanf("%d",&next);
				union_set(first,next);
			}
		}
		int p = find_set(0);
		printf("%d\n",count[p]);
	}
	return 0;
}

POJ1611

标签：lists   init   div   spi   break   find   rank   uniq   sum   

原文地址：http://www.cnblogs.com/zhaohongtian/p/6809016.html