HDU 4324 Triangle LOVE【拓扑排序】

 1 #include<iostream>  
 2 #include<cstdio>  
 3 #include<cstring> 
 4 #include <cmath> 
 5 #include<stack>
 6 #include<vector>
 7 #include<map> 
 8 #include<set>
 9 #include<queue> 
10 #include<algorithm>  
11 using namespace std;
12 
13 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)
14 
15 typedef long long LL;
16 const int INF = (1<<30)-1;
17 const int mod=1000000007;
18 const int maxn=2005;
19 
20 vector<int> g[maxn];
21 int in[maxn],ans[maxn];
22 char str[maxn];
23 int n;
24 
25 void toposort(){
26     queue<int> q;
27     for(int i=0;i<n;i++)
28     if(in[i]==0) q.push(i);
29     
30     int cnt=0;
31     while(!q.empty()){
32         int x=q.front();q.pop();
33         ans[++cnt]=x;
34         
35         for(int j=0;j<g[x].size();j++){
36             int m=g[x][j];
37             in[m]--;
38             if(in[m]==0) q.push(m);            
39         }
40     }
41     if(cnt==n) printf("No\n");
42     else printf("Yes\n");
43 }
44 
45 
46 
47 
48 int main(){
49     int T;
50     cin>>T;
51     for(int t=1;t<=T;t++){
52         cin>>n;
53         
54         memset(in,0,sizeof(in));
55         
56         for(int i=0;i<n;i++){
57             g[i].clear();
58             scanf("%s",str);
59             
60             for(int j=0;j<n;j++){
61                 if(str[j]==‘1‘) g[i].push_back(j),in[j]++;
62             }
63         }
64         printf("Case #%d: ",t);
65         toposort();    
66     }
67     return 0;
68 }