zoukankan      html  css  js  c++  java
  • HDU--1213--How Many Tables--并查集

    How Many Tables

    Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
    Total Submission(s): 9066    Accepted Submission(s): 4429


    Problem Description
    Today is Ignatius' birthday. He invites a lot of friends. Now it's dinner time. Ignatius wants to know how many tables he needs at least. You have to notice that not all the friends know each other, and all the friends do not want to stay with strangers.

    One important rule for this problem is that if I tell you A knows B, and B knows C, that means A, B, C know each other, so they can stay in one table.

    For example: If I tell you A knows B, B knows C, and D knows E, so A, B, C can stay in one table, and D, E have to stay in the other one. So Ignatius needs 2 tables at least.
     


     

    Input
    The input starts with an integer T(1<=T<=25) which indicate the number of test cases. Then T test cases follow. Each test case starts with two integers N and M(1<=N,M<=1000). N indicates the number of friends, the friends are marked from 1 to N. Then M lines follow. Each line consists of two integers A and B(A!=B), that means friend A and friend B know each other. There will be a blank line between two cases.
     


     

    Output
    For each test case, just output how many tables Ignatius needs at least. Do NOT print any blanks.
     


     

    Sample Input
    2 5 3 1 2 2 3 4 5 5 1 2 5
     


     

    Sample Output
    2 4

    #include <iostream>
    using namespace std;
    int father[1111];
    int Find(int a)  //找到祖先并所有家族成员指向祖先
    {
     return father[a]==a?a:father[a]=Find(father[a]);
    }
    void Union(int a,int b)  //把a家族并入b家族,a祖先指向b祖先
    {
     if(father[a]!=father[b])
     father[Find(a)]=Find(b);
    }
    int main (void)
    {
     int t,n,m,i,j,k,l;
     cin>>t;
     while(t--&&cin>>n>>m)
     {
      for(i=1;i<=n;i++)
       father[i]=i;
      for(i=0;i<m;i++)
      {
       cin>>k>>l;
       Union(k,l);
      }
      for(i=1,j=0;i<=n;i++)
      if(father[i]==i)  //计算有多少独立个体即计算多少家族即计算祖先数
      {
       j++;
      }
      cout<<j<<endl;
     }
     return 0;
    }

  • 相关阅读:
    js连等赋值与对象引用
    es6读书笔记(四)——顶层对象
    es6读书笔记(三)——const
    es6读书笔记(二)——块级作用域
    es6读书笔记(一)——let
    Idea工具使用junit运行单元测试(三):测试套件
    Python学习笔记(十二):列表生成式、三元表达式、字典排序
    python学习笔记(六):内置函数
    扫描歌曲
    为Activity设置特定权限才能启动
  • 原文地址:https://www.cnblogs.com/jiangu66/p/3198782.html
Copyright © 2011-2022 走看看