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  1. #include "bits/stdc++.h"
  2. using namespace std;
  3.  
  4. #define ll long long
  5. #define ld long double
  6. #define N 1000000
  7. const ll MOD = 1e9 + 7;
  8.  
  9. ll i, j, k, n, m, u, v;
  10. vector<ll> adj[N];
  11. ll vis[N] = {0};
  12. bool cycle = false;
  13. vector<ll> ans;
  14.  
  15. void dfs(ll x)
  16. {
  17.     vis[x] = 1;
  18.     for (auto it : adj[x])
  19.     {
  20.         if (!vis[it])
  21.             dfs(it);
  22.         else if (vis[it] == 1)
  23.             cycle = true;
  24.     }
  25.     vis[x] = 2;
  26.     ans.push_back(x);
  27. }
  28.  
  29. void top_sort(ll n)
  30. {
  31.     for (i = 1; i <= n; i++)
  32.     {
  33.         if (!vis[i])
  34.             dfs(i);
  35.     }
  36.     reverse(ans.begin(), ans.end());
  37. }
  38.  
  39. signed main()
  40. {
  41.     ios::sync_with_stdio(false);
  42.     cin.tie(nullptr);
  43.     cout.tie(nullptr);
  44.  
  45.     cin >> n >> m;
  46.     for (i = 0; i < m; i++)
  47.     {
  48.         cin >> u >> v;
  49.         adj[u].push_back(v);
  50.     }
  51.  
  52.     top_sort(n);
  53.  
  54.     if (cycle)
  55.         cout << "Sandro fails.";
  56.     else
  57.     {
  58.         for (auto it : ans)
  59.             cout << it << ' ';
  60.         cout << '\n';
  61.     }
  62. }
Success #stdin #stdout 0.02s 27956KB
comments (?)
stdin 
Standard input is empty
stdout 

	

		
	 
	
	
			

					
			
			
			
			
			
			
			
			

			
			
			
		

	
		
		

			


			                        
			
			

				

	
					
					 https://ideone.com/H4f5j1
					
					
					
					
					

												
problem TOPOSORT, based on SPOJ submission 35077092 (CPP14), 2025-10-09 08:06:01

												
						
						

					

					
					
					

						
language:

						
C++14 (gcc 8.3)

					

					

						
created:
								
						
1 day ago

					

					

						
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