Submission #169420

#	Time	Username	Problem	Language	Result	Execution time	Memory
169420		gs18103	Pipes (CEOI15_pipes)	C++14	80 / 100	5030 ms	13540 KiB

pipes

#include<bits/stdc++.h>
const int N = 1e5 + 5;
using namespace std;
 
vector <int> G[N];
int n, m, low[N], num[N], cnt;
 
struct dsu{
    int pset[N];
 
    void init(){
        for (int i = 1; i <= n; i++) pset[i] = i;
    }
 
    int find(int i) {return ((pset[i] == i) ? i : pset[i] = find(pset[i]));}
 
    bool Union(int i, int j){
        int u = find(i), v = find(j);
        if (u == v) return false;
        pset[u] = v;
        G[i].push_back(j);
        G[j].push_back(i);
        return true;
    }
} a[2];
 
void dfs(int u, int p){
    num[u] = low[u] = ++cnt; bool ck = false;
    for (auto v : G[u]){
        if (v == p && !ck) {ck = true; continue;}
        if (num[v]){
            low[u] = min(low[u], num[v]);
        }
        else{
            dfs(v, u);
            low[u] = min(low[u], low[v]);
        }
    }
    if (u != p && low[u] >= num[u]) cout << u << " " << p << "\n";
}
 
int main(){
    cin >> n >> m;
    a[0].init(); a[1].init();
    for (int i = 1; i <= m; i++){
        int u, v; cin >> u >> v;
        if (!a[0].Union(u, v)) a[1].Union(u, v);
    }
    for (int i = 1; i <= n; i++) if (!num[i]) dfs(i, i);
}

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