Submission #100620

#	Time	Username	Problem	Language	Result	Execution time	Memory
100620		doowey	Pipes (CEOI15_pipes)	C++14	100 / 100	1275 ms	12632 KiB

pipes

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

#define fi first
#define se second
#define mp make_pair
#define fastIO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);

const int N = (int)1e5+1;
int n1[N];
int n2[N];

int fin1(int x){
    if(n1[x]==x)
        return x;
    return n1[x]=fin1(n1[x]);
}

int fin2(int x){
    if(n2[x]==x)
        return x;
    return n2[x]=fin2(n2[x]);
}

bool merge1(int a, int b){
    a=fin1(a);
    b=fin1(b);
    if(a==b) return false;
    n1[a]=b;
    return true;
}

bool merge2(int a,int b){
    a=fin2(a);
    b=fin2(b);
    if(a==b) return false;
    n2[a]=b;
    return true;
}

vector<int> T[N];
int tin[N];
int low[N];
bool vis[N];
int timer;


void dfs(int u, int par){
    tin[u] = timer ++ ;
    low[u] = tin[u];
    vis[u] = true;
    int x;
    while(!T[u].empty()){
        x = T[u].back();
        T[u].pop_back();
        if(x==par) continue;
        if(vis[x]){
            low[u] = min(low[u], tin[x]);
        }
        else{
            dfs(x,u);
            low[u] = min(low[u], low[x]);
            if(tin[u]<low[x] && fin2(u) != fin2(x)){
                cout << u << " " << x << "\n";
            }
        }
    }
}

int main(){
    fastIO;
    int n, m;
    cin >> n >> m;
    for(int i = 1; i <= n; i ++ ){
        n1[i]=i;
        n2[i]=i;
    }
    int u, v;
    for(int i = 0 ; i < m ; i ++ ){
        cin >> u >> v;
        if(merge1(u,v)){
            T[u].push_back(v);
            T[v].push_back(u);
        }
        else if(merge2(u,v)){
            T[u].push_back(v);
            T[v].push_back(u);
        }

    }
    for(int i = 1; i <= n; i ++ )if(!vis[i]) dfs(i,-1);
    return 0;
}

• 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: 10 / 10
• Subtask 10: 10 / 10