[2016-03-15][HDU][1213][How Many Tables]

• 时间:2016-03-15 16:19:15 星期二

• 题目编号:[2016-03-15][HDU][1213][How Many Tables]

• 题目大意:请朋友吃饭,每个朋友都不喜欢和不认识的人在一桌,给出认识的关系,问至少要多少桌

• 输入:

  • t组数
  • 每组数据
  • n m
  • m行 u v 表示u 和 v 认识

• 输出:

  • 最少

• 分析:并查集,求集合的数目

#ifdef _WORK_
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
using namespace std;
typedef long long LL;
#define CLR(x,y) memset((x),(y),sizeof((x)))
#define FOR(x,y,z) for(int (x)=(y);(x)<(z);++(x))
#define FORD(x,y,z) for(int (x)=(y);(x)>=(z);--(x))
const int maxn = 1000 + 100;
int fa[maxn],mrank[maxn];
void ini(int n){
        memset(mrank,0,sizeof(mrank));
        for(int i = 0; i <= n;++i){
                fa[i] = i;
        }
}
int fnd(int x){
        return x ==fa[x]?x:fa[x] = fnd(fa[x]);
}
void uni(int x,int y){
        x = fnd(x);y = fnd(y);
        if(x == y)      return ;
        if(mrank[x] < mrank[y]){
                fa[x] = y;
        }else {
                fa[y] = x;
                if(mrank[x] == mrank[y])        ++mrank[x]; 
        }
}
int main(){
        //freopen("in.txt","r",stdin);
        //freopen("out.txt","w",stdout);
        int t;
        scanf("%d",&t);
        while(t--){
                int n,m;
                scanf("%d%d",&n,&m);
                ini(n);
                FOR(i,0,m){
                        int u,v;
                        scanf("%d%d",&u,&v);
                        uni(u,v);
                }
                int ans = 0;
                FOR(i,1,n + 1){ if(fa[i] == i)
                        ++ans;
                }
                printf("%d\n",ans);
        }
        return 0;
}
#endif

[2016-03-15][HDU][1213][How Many Tables]

原文：http://www.cnblogs.com/qhy285571052/p/8ed2cdfd7f05329d8539aa040a774553.html