제출 #434320

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
434320		Monchito	Simurgh (IOI17_simurgh)	C++14	0 / 100	0 ms	204 KiB

simurgh

#include "simurgh.h"
using namespace std;

vector<int> U, V, ans;
int N, M;
bool flag = false;

void DFS(int u, vector<bool>& vis, vector<vector<int>>& G) {
    vis[u] = true;
    for(int v : G[u]) {
        if(!vis[v]) DFS(v, vis, G); 
    }
}

void test(int msk) {
    bool can = true;
    vector<int> r(N-1);
    vector<vector<int>> G(N);
    vector<int> nodes;
    vector<bool> vis(N, false);

    for(int i=0, j=0; j < N-1; i++) {
        if((msk & (1<<i)) != 0) {
            r[j] = i;
            j++;
        }
    }

    for(int i=0; i<N-1; i++) {
        int j = r[i];
        G[U[j]].push_back(V[j]);
        G[V[j]].push_back(U[j]);
        nodes.push_back(U[j]);
        nodes.push_back(V[j]);
    }

    DFS(nodes[0], vis, G);

    for(int it : nodes)
        if(!vis[it]) can = false;

    if(!can) return;
    if(count_common_roads(r) == N-1) {
        ans = r;
        flag = true;
    }
}

void solve(int msk) {
    if(flag) return;

    if(__builtin_popcount(msk) == N-1) {
        test(msk);
        return;
    }

    for(int i=0; i<M; i++) {
        if((msk & (1<<i)) != 0) continue;
        int nmsk = msk | (1<<i);
        solve(nmsk);
    }
}

vector<int> find_roads(int n, vector<int> u, vector<int> v) {
    N = n;
    M = (int)u.size();
    U = u;
    V = v;

    ans = vector<int>(n-1);
    solve(0);

    return ans;
}

• Subtask 1: 0 / 13
• Subtask 2: 0 / 17
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30