제출 #292873

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
292873		Atill83	통행료 (IOI18_highway)	C++14	12 / 100	309 ms	262148 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>
#define ff first
#define ss second
using namespace std;
typedef pair<int, int> pii;
vector<int> sor;
vector<int> cnd;
const int MAXN = (int) 9e4 + 5;
vector<pii> adj[MAXN];
int open[MAXN];
int dep[MAXN];
long long der;
void dfs(int v, int par){
    if(dep[v] == der) {cnd.push_back(v); return;}
    for(pii u: adj[v]){
        int j = u.ff;
        if(j != par){
            dep[j] = dep[v] + 1;
            dfs(j, v);
        }
    }
}

bool dfs1(int v, int par){
    if(open[v]) return 1;
    bool vardi = 0;
    for(pii u: adj[v]){
        if(u.ff == par) continue;
        bool var = dfs1(u.ff, v);
        vardi |= var;
        if(var){
            sor[u.ss] = 0;
        }
    }
    return vardi;
}

void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
    int M = U.size();
    int s = 0, t;
    for(int i = 0; i < M; i++) {
        sor.push_back(0);
        adj[U[i]].push_back({V[i], i});
        adj[V[i]].push_back({U[i], i});
    }
    der = ask(sor) / A;

    dfs(0, -1);

    int l = 0, r = cnd.size() - 1;

    while(l < r){
        int m = (l + r) / 2;
        for(int i = 0; i < M; i++) sor[i] = 1;
        for(int i = l; i <= m; i++){
            open[cnd[i]] = 1;
        }
        dfs1(0, -1);
        for(int i = l; i <= m; i++){
            open[cnd[i]] = 0;
        }
        long long dr = ask(sor);
        if(dr == der*A){
            r = m;
        }else{
            l = m + 1;
        }
    }
    t = cnd[l];
    answer(s,t);
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 0 / 6
• Subtask 4: 0 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31