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Submission #97604

# Submission time Handle Problem Language Result Execution time Memory
97604 2019-02-17T12:46:17 Z dalgerok Pipes (CEOI15_pipes) C++14
100 / 100
 1198 ms 10660 KB 
#include<bits/stdc++.h>
using namespace std;


const int N = 1e5 + 5;



int n, m;
int p[2][N];
int tin[N], fup[N], timer;

int E, Y[4 * N], lst[N], prv[4 * N];
void add_edge(int x, int y){
    Y[++E] = y;
    if(lst[x] == 0){
        lst[x] = E;
    }
    else{
        prv[E] = lst[x];
        lst[x] = E;
    }

    Y[++E] = x;
    if(lst[y] == 0){
        lst[y] = E;
    }
    else{
        prv[E] = lst[y];
        lst[y] = E;
    }
}

int dsu_get(int x, int v){
    return p[x][v] == v ? v : p[x][v] = dsu_get(x, p[x][v]);
}

void dfs(int v, int pr = 0){
    tin[v] = fup[v] = ++timer;
    bool was = false;
    for(int i = lst[v]; i != 0; i = prv[i]){
        int to = Y[i];
        if(to == pr){
            if(was){
                fup[v] = min(fup[v], tin[to]);
            }
            was = true;
            continue;
        }
        if(!tin[to]){
            dfs(to, v);
            if(fup[to] > tin[v]){
                cout << v << " " << to << "\n";
            }
            fup[v] = min(fup[v], fup[to]);
        }
        else{
            fup[v] = min(fup[v], tin[to]);
        }
    }

}
int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        p[0][i] = p[1][i] = i;
    }
    for(int i = 1; i <= m; i++){
        int x, y;
        cin >> x >> y;
        if(dsu_get(0, x) == dsu_get(0, y)){
            if(dsu_get(1, x) == dsu_get(1, y)){
                continue;
            }
            p[1][dsu_get(1, x)] = dsu_get(1, y);
        }
        else{
            p[0][dsu_get(0, x)] = dsu_get(0, y);
        }
        add_edge(x, y);
    }
    for(int i = 1; i <= n; i++){
        if(!tin[i]){
            //cout << "KEK " << i << " " << tin[i] << "\n";
            dfs(i);
        }
    }
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 868 KB Output is correct
2 Correct 5 ms 640 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 105 ms 688 KB Output is correct
2 Correct 98 ms 564 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 162 ms 1400 KB Output is correct
2 Correct 190 ms 888 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 282 ms 2836 KB Output is correct
2 Correct 253 ms 2472 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 383 ms 7628 KB Output is correct
2 Correct 334 ms 4428 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 608 ms 8708 KB Output is correct
2 Correct 586 ms 5920 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 857 ms 10656 KB Output is correct
2 Correct 781 ms 6196 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1076 ms 10660 KB Output is correct
2 Correct 949 ms 6208 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1198 ms 10188 KB Output is correct
2 Correct 1126 ms 7388 KB Output is correct