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Submission #478972

# Submission time Handle Problem Language Result Execution time Memory
478972 2021-10-09T09:25:12 Z hjc4vr Pipes (CEOI15_pipes) C++14
100 / 100
 1264 ms 14864 KB 
#include <bits/stdc++.h>
using namespace std;
int ufds1[100005],ufds2[100005],low[100005],depths[100005];
vector<int> adj[100005];
int find(int a,int par[]){
    if (par[a]==a) return a;
    par[a] = find(par[a],par);
    return par[a];
}

void dfs(int cur,int par){
    depths[cur] = depths[par] + 1;
    low[cur] = depths[cur];
    bool check= false;
    for (auto it: adj[cur]){
        if (check == false && it==par){
            check = true;
            continue;
        }
        else{
        if (depths[it]==-1){
            dfs(it,cur);
            low[cur] = min(low[cur],low[it]);
            if (low[it]>depths[cur]){
                cout << cur << ' ' << it << '\n';
            }
        }else{
            low[cur] = min(low[cur],depths[it]);
            }
        }
    }
}


int32_t main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n,m;cin>>n>>m;
    fill(depths,depths+100005,-1);
    for (int i=1;i<=n;++i){
        ufds1[i] = i;
        ufds2[i] = i;
    }
    for (int i=0;i<m;++i){
        int a,b;cin>>a>>b;
        int pa = find(a,ufds1), pb = find(b,ufds1);
        if (pa!=pb){
            adj[a].push_back(b);
            adj[b].push_back(a);
            ufds1[pb] = pa;
        }else{ // it is a back edge
            int ba = find(a,ufds2), bb = find(b,ufds2);
            if (ba!=bb){
                adj[a].push_back(b);
                adj[b].push_back(a);
                ufds2[bb] = ba;
            }
        }
    }
    for (int i=1;i<=n;++i){
        if (depths[i]==-1){
            dfs(i,0);
        }
    }
}
   
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Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3020 KB Output is correct
2 Correct 2 ms 3020 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 3548 KB Output is correct
2 Correct 7 ms 3404 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 139 ms 3368 KB Output is correct
2 Correct 104 ms 3212 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 197 ms 4156 KB Output is correct
2 Correct 217 ms 3628 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 290 ms 5860 KB Output is correct
2 Correct 268 ms 5416 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 392 ms 11412 KB Output is correct
2 Correct 368 ms 7368 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 615 ms 12556 KB Output is correct
2 Correct 738 ms 9292 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 821 ms 14864 KB Output is correct
2 Correct 780 ms 9128 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 977 ms 14864 KB Output is correct
2 Correct 924 ms 9204 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1227 ms 14232 KB Output is correct
2 Correct 1264 ms 11156 KB Output is correct