题目链接：

题目是中文题面我就不说题意了，要看题面的请点击上方链接~

代码实现如下：

1 #include 
     
       2 #include 
      
        3 #include 
       
         4 #include 
        
          5 using namespace std; 6  7 const int maxn = 1e5 + 7; 8 int t, n, m, num, u, v; 9 int InDeg[maxn];10 vector
         
           G[maxn];11 12 bool topsort() {13     num = 0;14     queue
          
            q;15 for(int i = 1; i <= n; i++) {16 if(InDeg[i] == 0) {17 q.push(i);18 }19 }20 int x;21 while(!q.empty()) {22 x = q.front(), q.pop();23 num++;24 int s = G[x].size();25 for(int i = 0; i < s; i++) {26 if(--InDeg[G[x][i]] == 0) {27 q.push(G[x][i]);28 }29 }30 }31 return num == n;32 }33 34 int main() {35 scanf("%d", &t);36 while(t--) {37 scanf("%d%d", &n, &m);38 for(int i = 0; i <= n; i++) {39 G[i].clear();40 InDeg[i] = 0;41 }42 for(int i = 0; i < m; i++) {43 scanf("%d%d", &u, &v);44 G[u].push_back(v);45 InDeg[v]++;46 }47 if(topsort()) {48 printf("Correct\n");49 } else {50 printf("Wrong\n");51 }52 }53 return 0;54 }