HDOJ---1856 More is better[并查集求节点最多的树的节点数量]

More is better

Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 327680/102400 K (Java/Others)
Total Submission(s): 6438    Accepted Submission(s): 2383


Problem Description
Mr Wang wants some boys to help him with a project. Because the project is rather complex, the more boys come, the better it will be. Of course there are certain requirements.

Mr Wang selected a room big enough to hold the boys. The boy who are not been chosen has to leave the room immediately. There are 10000000 boys in the room numbered from 1 to 10000000 at the very beginning. After Mr Wang's selection any two of them who are still in this room should be friends (direct or indirect), or there is only one boy left. Given all the direct friend-pairs, you should decide the best way.
 

 

Input
The first line of the input contains an integer n (0 ≤ n ≤ 100 000) - the number of direct friend-pairs. The following n lines each contains a pair of numbers A and B separated by a single space that suggests A and B are direct friends. (A ≠ B, 1 ≤ A, B ≤ 10000000)
 

 

Output
The output in one line contains exactly one integer equals to the maximum number of boys Mr Wang may keep.
 

 

Sample Input
4 1 2 3 4 5 6 1 6 4 1 2 3 4 5 6 7 8
 

 

Sample Output
4 2
Hint
A and B are friends(direct or indirect), B and C are friends(direct or indirect), then A and C are also friends(indirect). In the first sample {1,2,5,6} is the result. In the second sample {1,2},{3,4},{5,6},{7,8} are four kinds of answers.
 

 

Author
lxlcrystal@TJU
 

 

Source
 

 

Recommend
lcy
 
 
 
 
 
 
 
用一个变量存最大值
code:
复制代码
 1 #include <iostream>   
 2 #include <iomanip>   
 3 #include <fstream>   
 4 #include <sstream>   
 5 #include <algorithm>   
 6 #include <string>   
 7 #include <set>   
 8 #include <utility>   
 9 #include <queue>   
10 #include <stack>   
11 #include <list>   
12 #include <vector>   
13 #include <cstdio>   
14 #include <cstdlib>   
15 #include <cstring>   
16 #include <cmath>   
17 #include <ctime>   
18 #include <ctype.h> 
19 using namespace std;
20 
21 #define MAXN 10000010
22 
23 int father[MAXN];
24 int cnt[MAXN];
25 int maxnum;
26 
27 void init()
28 {
29     for(int i=0;i<MAXN;i++)
30     {
31         father[i]=i;
32         cnt[i]=1;
33     }
34 }
35 
36 int findset(int v)
37 {
38     int t1,t2=v;
39     while(v!=father[v])
40         v=father[v];
41     while(t2!=father[t2])
42     {
43         t1=father[t2];
44         father[t2]=v;
45         t2=t1;
46     }
47     return v;
48 }
49 
50 void Union(int a,int b)
51 {
52     a=findset(a);
53     b=findset(b);
54     if(a!=b)
55     {
56         father[a]=b;
57         cnt[b]+=cnt[a];
58         maxnum=maxnum>cnt[b]?maxnum:cnt[b];
59     }
60 }
61 
62 int main()
63 {
64     int n;
65     int a,b;
66     while(~scanf("%d",&n))
67     {
68         maxnum=1;
69         init();
70         while(n--)
71         {
72             scanf("%d%d",&a,&b);
73             Union(a,b);
74         }
75         printf("%d\n",maxnum);
76     }
77     return 0;
78 }
复制代码

 

posted @   max_xbw  阅读(351)  评论(0编辑  收藏  举报
编辑推荐:
· .NET 9 new features-C#13新的锁类型和语义
· Linux系统下SQL Server数据库镜像配置全流程详解
· 现代计算机视觉入门之:什么是视频
· 你所不知道的 C/C++ 宏知识
· 聊一聊 操作系统蓝屏 c0000102 的故障分析
阅读排行:
· 不到万不得已,千万不要去外包
· C# WebAPI 插件热插拔(持续更新中)
· .NET 9 new features-C#13新的锁类型和语义
· 会议真的有必要吗?我们产品开发9年了,但从来没开过会
· 《SpringBoot》EasyExcel实现百万数据的导入导出
                                                                                                                     
点击右上角即可分享
微信分享提示