POJ 2419 Forests（模拟）

题目链接：

https://cn.vjudge.net/problem/POJ-2419

题目描述：

If a tree falls in the forest, and there's nobody there to hear, does it make a sound? This classic conundrum was coined by George Berkeley (1685-1753), the Bishop and influential Irish philosopher whose primary philosophical achievement is the advancement of what has come to be called subjective idealism. He wrote a number of works, of which the most widely-read are Treatise Concerning the Principles of Human Knowledge (1710) and Three Dialogues between Hylas and Philonous (1713) (Philonous, the "lover of the mind," representing Berkeley himself).

Input

A forest contains T trees numbered from 1 to T and P people numbered from 1 to P. Standard input consists of a line containing P and T followed by several lines, containing a pair of integers i and j, indicating that person i has heard tree j fall.

Output

People may have different opinions as to which trees, according to Berkeley, have made a sound. Output how many different opinions are represented in the input? Two people hold the same opinion only if they hear exactly the same set of trees. You may assume that P < 100 and T < 100.

Sample Input

3 4
1 2
3 3
1 3
2 2
3 2
2 4

Sample Output

2

 /*
 题意描述
 有p个人去听t棵树倒下的声音，问有几种不同的观点数

 解题思路
 用二维数组记录i听到j倒下，如果某个人听到的结果和另一个完全相同，说明这两个人是一种观点，需要总观点数减一
 */
 #include<cstdio>
 #include<cstring>
 const int maxn=+;

 bool g[maxn][maxn];
 int t,p;
 int common(int a,int b);

 int main()
 {
     int x,y;
     memset(g,,sizeof(bool)*maxn*maxn);
     scanf("%d%d",&p,&t);
     while(scanf("%d%d",&x,&y) != EOF){
         g[x][y]=;
     }
     int sum=p;
     for(int i=;i<=p-;i++){
         for(int j=i+;j<=p;j++){
             if(common(i,j)){
                 sum--;
                 break;//遇到一个重复以后，总观点数减1后直接判断下一个
             }
         }
     }
     printf("%d\n",sum);
     return ;
 } 

 int common(int a,int b)
 {
     for(int i=;i<=t;i++){
         if(g[a][i] != g[b][i])
             return ;
     }
     return ;
 }