代码:
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
struct node
{
vector<int>u;
int val, in_degree;
node() {
val = in_degree = 0;
u.clear();
}
};
class Graph
{
private:
vector<node>a;
int edge_num, node_num;
public:
Graph();
Graph(int node_num);
void addEdge(int s_node, int t_node);
vector<int> getAns();
};
Graph::Graph() {
this->a.clear();
this->edge_num = this->node_num = 0;
}
Graph::Graph(int node_num) {
a.clear();
a.resize(node_num + 1);
this->node_num = node_num;
this->edge_num = 0;
}
void Graph::addEdge(int s_node, int t_node) {
this->a[s_node].u.push_back(t_node);
this->a[t_node].in_degree++;
this->edge_num++;
}
vector<int> Graph::getAns() {
vector<int> ret;
queue<int>q;
for (int i = 1; i <= node_num; i++) {
if (a[i].in_degree == 0) {
q.push(i);
}
}
while (!q.empty()) {
node& now = a[q.front()];
ret.push_back(q.front());
q.pop();
for (int i = 0; i < now.u.size(); i++) {
a[now.u[i]].in_degree--;
if (a[now.u[i]].in_degree == 0) {
q.push(now.u[i]);
}
}
}
return ret;
}
int main() {
int T;
cin >> T;
while (T--) {
int n, m;
cin >> n >> m;
Graph ans = Graph(n);
while (m--) {
int s, t;
cin >> s >> t;
ans.addEdge(s, t);
}
if (ans.getAns().size() == n) {
cout << "Correct" << endl;
}
else {
cout << "Wrong" << endl;
}
}
}