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  1. #include <vector>
  2. #include <iostream>
  3. #include <unordered_map>
  4. #include <unordered_set>
  5. using namespace std;
  6.  
  7. void dfs(unordered_map<int, vector<int>> followMap, unordered_set<int>& visited, int follower) {
  8. 	visited.insert(follower);
  9. 	for (const auto& follow : followMap[follower]) {
  10. 		if (visited.find(follow) == visited.end()) {
  11. 			visited.insert(follow);
  12. 			dfs(followMap, visited, follow);
  13. 		}
  14. 	}
  15. }
  16.  
  17. int main() {
  18. 	int total_mem = 0, mem, total_edge = 0, follower, following;
  19. 	unordered_map<int, vector<int>> followMap;
  20. 	cin >> total_mem;
  21. 	unordered_set<int> visited(total_mem);
  22. 	for (int i = 0; i < total_mem; i++)	cin >> mem;
  23. 	cin >> total_edge;
  24. 	for (int i = 0; i < total_edge; i++) {
  25. 		cin >> follower >> following;
  26. 		if (followMap.find(follower) == followMap.end())
  27. 			followMap[follower] = vector<int>();
  28. 		followMap[follower].push_back(following);
  29. 	}
  30. 	cin >> follower >> following;
  31. 	dfs(followMap, visited, follower);
  32. 	int canReach = visited.find(following) != visited.end() ? 1 : 0;
  33. 	cout << canReach;
  34. 	return 0;
  35. }
Success #stdin #stdout 0.01s 5280KB
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1
https://ideone.com/pAI9GU
language:
C++ (gcc 8.3)
created:
5 days ago
visibility:
public

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