Submission #527146

#	Time	Username	Problem	Language	Result	Execution time	Memory
527146		chicken337	Pipes (CEOI15_pipes)	C++14	100 / 100	998 ms	14160 KiB

pipes

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100005;
 
int v, e, ID = 0;
vector<int> num, low;
vector<int> adj[MAXN];

struct UFDS{
    vector<int> p;
    vector<char> r;
    UFDS(){
        p.resize(v); r.resize(v);
        for(int i = 0; i < v; i ++)
            p[i] = i, r[i] = 0;
    }
    int root(int x){
        if(p[x] == x) return x;
        return p[x] = root(p[x]);
    }
    bool connected(int x, int y){
        return root(x) == root(y);
    }
    void connect(int x, int y){
        x = root(x), y = root(y);
        if(r[x] < r[y]) swap(x, y);
        if(r[x] == r[y]) r[x] ++;
        p[y] = x;
    }
};
 
void dfs(int x, int par){
    num[x] = low[x] = ID ++;
    for(int nxt : adj[x]){
        if(num[nxt] == -1){
            dfs(nxt, x);
            if(num[x] < low[nxt])
                cout << x+1 << ' ' << nxt+1 << '\n';
            low[x] = min(low[x], low[nxt]);
        } else if(nxt != par){
            low[x] = min(low[x], num[nxt]);
        } else par = -1;
    }
}
 
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
 
    cin >> v >> e; int a, b;
    UFDS ua = UFDS();
    UFDS ub = UFDS();
    num.assign(v, -1);
    low.assign(v, -1);
    for(int i = 0; i < e; i ++){
        cin >> a >> b;
        if(!ua.connected(a-1, b-1)){
            adj[a-1].push_back(b-1);
            adj[b-1].push_back(a-1);
            ua.connect(a-1, b-1);
        } else if(!ub.connected(a-1, b-1)){
            adj[a-1].push_back(b-1);
            adj[b-1].push_back(a-1);
            ub.connect(a-1, b-1);
        }
    }
    for(int i = 0; i < v; i ++)
        if(num[i] == -1)
            dfs(i, -1);
}

• 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