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37 | class Solution {
public:
bool canFinish(int numCourses, vector<vector<int>>& prerequisites) {
std::vector<vector<int>> G(numCourses);
std::vector<int> inDegree(numCourses, 0);
std::queue<int> Q;
std::vector<bool> vis(numCourses, false);
for (auto p : prerequisites) {
int from = p[0];
int to = p[1];
G[from].push_back(to);
inDegree[to]++;
}
for (int i = 0; i < numCourses; i++)
if (inDegree[i] == 0)
Q.push(i);
while(!Q.empty()) {
int cur = Q.front();
vis[cur] = true;
Q.pop();
for (auto adj : G[cur]) {
inDegree[adj]--;
if(inDegree[adj] == 0)
Q.push(adj);
}
}
for (auto v : vis)
if (!v)
return false;
return true;
}
};
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