제출 #1081692

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1081692		TB_	Pipes (CEOI15_pipes)	C++17	100 / 100	721 ms	5340 KiB

pipes

#include <bits/stdc++.h>

using namespace std;

#define ll int
#define fo(i, n) for(ll i = 0; i<(n); i++)
#define F first 
#define S second
#define pb push_back
#define deb(x) cout << #x << " = " << (x) << endl
#define deb2(x, y) cout << #x << " = " << (x)  << ",  " << #y << " = " << (y) << endl


typedef vector<int> vl;
typedef vector<vl> vvl;


struct UnionFind{
    int n;
    vl p;
    UnionFind(int n){
        p.resize(n);
        fo(i, n) p[i] = i;
    }

    int find(int x){
        if(p[x] == x) return x;
        return p[x] = find(p[x]);
    }

    bool same(int a, int b){
        return find(a) == find(b);
    }

    void unite(int a, int b){
        a = find(a);
        b = find(b);
        if(rand()%2) swap(a, b);
        p[b] = a;
    }
};


int main(){
    cin.tie(0)->sync_with_stdio(0);

    int n, m, from, to;
    cin >> n >> m;
    vl xorv(n, 0), amount(n, 0), hash(n, 0);
    UnionFind uf(n);
    mt19937 rng(42);
    fo(i, m){
        cin >> from >> to;
        from--; to--;
        if(uf.same(from, to)){
            ll val = rng();
            hash[from]^=val;
            hash[to]^=val;
        }else{
            amount[from]++;
            amount[to]++;
            xorv[from]^=to;
            xorv[to]^=from;
            uf.unite(from, to);
        }
    }


    ll pos;
    fo(i, n){
        pos=i;
        while(1){
            if(amount[pos] != 1) break;
            ll edge = xorv[pos];
            if(!hash[pos]) cout << pos+1 << " " << edge+1 << endl;
            amount[pos]--;
            amount[edge]--;
            xorv[pos]^=edge;
            xorv[edge]^=pos;
            hash[edge]^=hash[pos];
            pos = edge;
            if(amount[edge] != 1) break;
        }
    }


    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