Submission #623858

#	Time	Username	Problem	Language	Result	Execution time	Memory
623858		Iwanttobreakfree	Pipes (CEOI15_pipes)	C++17	30 / 100	2391 ms	65536 KiB

pipes

#include <iostream>
#include <vector>
using namespace std;
#define pii pair<int,int>
vector<pii> ans;
int timer=0;
int dfs(int a,int par,vector<vector<pii>>& g,vector<int>& min_in,vector<int>& t){
    t[a]=timer++;
    min_in[a]=t[a];
    for(auto x:g[a]){
        if(x.second==par)continue;
        if(t[x.first]==-1){
            int up=dfs(x.first,x.second,g,min_in,t);
            if(up>t[a])ans.push_back({a+1,x.first+1});
        }
        min_in[a]=min(min_in[a],min_in[x.first]);
    }
    //cout<<a<<' '<<min_in[a]<<' '<<t[a]<<'\n';
    return min_in[a];
}
int main(){
    int n,m,x,y;
    cin>>n>>m;
    vector<vector<pair<int,int>>> g(n,vector<pair<int,int>>());
    vector<int> t(n,-1),min_in(n);
    for(int i=0;i<m;i++){
        cin>>x>>y;
        x--;y--;
        g[x].push_back({y,i});
        g[y].push_back({x,i});
    }
    for(int i=0;i<n;i++)if(t[i]==-1)dfs(i,-1,g,min_in,t);
    //cout<<endl;
    for(auto x:ans)cout<<x.first<<' '<<x.second<<'\n';
}

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