| 13 | } |
| 14 | |
| 15 | bool topo_sort(vector<int> vec[], int v) |
| 16 | { |
| 17 | vector<int> indegree(v, 0); |
| 18 | for (int i = 0; i < v; i++) |
| 19 | { |
| 20 | for (int j = 0; j < vec[i].size(); j++) |
| 21 | { |
| 22 | int adjacent = vec[i][j]; |
| 23 | indegree[adjacent]++; |
| 24 | } |
| 25 | } |
| 26 | queue<int> q; |
| 27 | for (int i = 0; i < indegree.size(); i++) |
| 28 | { |
| 29 | if (indegree[i] == 0) |
| 30 | { |
| 31 | q.push(i); |
| 32 | } |
| 33 | } |
| 34 | int count = 0; |
| 35 | while (q.empty() == false) |
| 36 | { |
| 37 | int curr = q.front(); |
| 38 | q.pop(); |
| 39 | |
| 40 | count++; |
| 41 | for (int i = 0; i < vec[curr].size(); i++) |
| 42 | { |
| 43 | int adjacent = vec[curr][i]; |
| 44 | |
| 45 | indegree[adjacent]--; |
| 46 | if (indegree[adjacent] == 0) |
| 47 | { |
| 48 | q.push(adjacent); |
| 49 | } |
| 50 | } |
| 51 | } |
| 52 | return count == v; |
| 53 | } |
| 54 | |
| 55 | int main() |
| 56 | { |