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Submission #96161

# Submission time Handle Problem Language Result Execution time Memory
96161 2019-02-06T14:53:30 Z popovicirobert Pipes (CEOI15_pipes) C++14
100 / 100
 1261 ms 13416 KB 
#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
// 217
// 44

using namespace std;

struct DSU {
    vector <int> par;
    int n;
    inline void init(int _n) {
        n = _n;
        par.resize(n + 1);
    }
    int root(int x) {
        if(par[x] == 0)
            return x;
        return par[x] = root(par[x]);
    }
    inline void join(int x, int y) {
        x = root(x), y = root(y);
        if(x != y) {
            par[x] = y;
        }
    }
};

const int MAXN = (int) 1e5;

vector <int> g[MAXN + 1];
stack <int> stk;

inline void addEdge(int x, int y) {
    g[x].push_back(y);
    g[y].push_back(x);
}

int lvl[MAXN + 1], low[MAXN + 1];

void dfs(int nod, int par) {
    stk.push(nod);
    lvl[nod] = lvl[par] + 1;
    low[nod] = lvl[nod];
    int cnt = 0;
    for(auto it : g[nod]) {
        if(lvl[it] == 0) {
            dfs(it, nod);
            low[nod] = min(low[nod], low[it]);
            if(low[it] == lvl[it]) {
                while(stk.top() != it) {
                    stk.pop();
                }
                stk.pop();
                cout << nod << " " << it << "\n";
            }
        }
        else {
            if(it == par) {
                if(cnt == 1) {
                    low[nod] = min(low[nod], lvl[it]);
                }
                cnt++;
            }
            else {
                low[nod] = min(low[nod], lvl[it]);
            }
        }
    }
}

int main() {
    //ifstream cin("B.in");
    //ofstream cout("B.out");
    int i, n, m;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    cin >> n >> m;
    DSU dsu1, dsu2;
    dsu1.init(n);
    dsu2.init(n);
    for(i = 1; i <= m; i++) {
        int x, y;
        cin >> x >> y;
        if(dsu1.root(x) == dsu1.root(y)) {
            if(dsu2.root(x) != dsu2.root(y)) {
                dsu2.join(x, y);
                addEdge(x, y);
            }
        }
        else {
            dsu1.join(x, y);
            addEdge(x, y);
        }
    }
    for(i = 1; i <= n; i++) {
        if(lvl[i] == 0) {
            dfs(i, 0);
        }
    }
    //cin.close();
    //cout.close();
    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2688 KB Output is correct
2 Correct 4 ms 2688 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 3116 KB Output is correct
2 Correct 8 ms 2944 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 103 ms 3036 KB Output is correct
2 Correct 97 ms 2936 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 175 ms 3728 KB Output is correct
2 Correct 235 ms 3324 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 290 ms 5292 KB Output is correct
2 Correct 246 ms 4992 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 427 ms 10336 KB Output is correct
2 Correct 378 ms 7388 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 638 ms 11376 KB Output is correct
2 Correct 633 ms 8956 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 865 ms 13416 KB Output is correct
2 Correct 844 ms 9344 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1057 ms 13416 KB Output is correct
2 Correct 990 ms 9340 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1261 ms 12908 KB Output is correct
2 Correct 1184 ms 10464 KB Output is correct