Submission #669292

#	Time	Username	Problem	Language	Result	Execution time	Memory
669292		manizare	Pipes (CEOI15_pipes)	C++11	70 / 100	998 ms	18896 KiB

pipes

#include <bits/stdc++.h>
#define all(a) a.begin(),a.end() 
#define pb push_back
using namespace std ;
const int maxn = 2e5+100 , maxq =5002 , inf = 2e17 + 100 , mod = 1e9 + 7 ;
vector <pair <int , int > >G[maxn] ;
int par[maxn] , par2[maxn] , p[maxn] , dp[maxn] , mark[maxn] , dis[maxn] , j[maxn];
int find(int v){
	if(par[v] == v)return v; 
	return par[v] = find(par[v]);
}
int find2(int v){
	if(par2[v] == v)return v; 
	return par2[v] = find2(par2[v]) ;
}

void dfs(int v){
	mark[v] = 1; 
	for(int i = 0 ; i < G[v].size() ; i++){
		int u = G[v][i].first , o = G[v][i].second; ;
		if(mark[u] == 1){
			if(j[o] == 0 && dis[u] < (dis[v])){
				dp[v] ++ ;
				dp[u]--;
			}
			continue ;
		}
		dis[u] = dis[v] + 1; 
		p[u] = v; 
		j[o] = 1; 
		dfs(u);
		dp[v] += dp[u] ;
	}
}

signed main(){	
	ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
	int n , m ;
	cin >> n >> m ;
	for(int i= 1 ; i <= n ; i++){
		par[i] = i ;
		par2[i] = i ; 
	}
	int c = 1; 
	for(int i =1 ; i <= m ; i++){
		int v  , u ;
		cin >> v >> u ;
		int v1 = find(v) , u1 = find(u);
		if(v1 != u1){
			G[v].pb({u , c}) ;
			G[u].pb({v , c});c++;
			par[v1] = u1 ;
		}else if(find2(v) != find2(u)){
			par2[find2(v)] = find2(u);
			G[v].pb({u,c}) ;
			G[u].pb({v,c});c++;
		}
	}
	for(int i = 1; i <= n ; i++){
		if(mark[i] == 0)dfs(i); 
	}
	for(int i = 1; i <= n ; i++){
		if(dp[i] == 0 && p[i] != 0){
			cout << i << " " << p[i] << "\n";
		}
	}
}

Compilation message (stderr)

pipes.cpp:5:52: warning: overflow in conversion from 'double' to 'int' changes value from '2.000000000000001e+17' to '2147483647' [-Woverflow]
    5 | const int maxn = 2e5+100 , maxq =5002 , inf = 2e17 + 100 , mod = 1e9 + 7 ;
      |                                               ~~~~~^~~~~
pipes.cpp: In function 'void dfs(int)':
pipes.cpp:19:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |  for(int i = 0 ; i < G[v].size() ; i++){
      |                  ~~^~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10