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Submission #97605

# Submission time Handle Problem Language Result Execution time Memory
97605 2019-02-17T12:47:13 Z dalgerok Pipes (CEOI15_pipes) C++14
100 / 100
 1242 ms 10656 KB 
#include<bits/stdc++.h>
using namespace std;


const int N = 1e5 + 1;



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 768 KB Output is correct
2 Correct 4 ms 640 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 99 ms 760 KB Output is correct
2 Correct 94 ms 592 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 163 ms 1336 KB Output is correct
2 Correct 192 ms 888 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 323 ms 2808 KB Output is correct
2 Correct 236 ms 2436 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 387 ms 7672 KB Output is correct
2 Correct 376 ms 4540 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 616 ms 8696 KB Output is correct
2 Correct 592 ms 6136 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 814 ms 10652 KB Output is correct
2 Correct 789 ms 6208 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1034 ms 10656 KB Output is correct
2 Correct 1059 ms 6336 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1242 ms 10188 KB Output is correct
2 Correct 1155 ms 7308 KB Output is correct