제출 #878242

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
878242		boris_mihov	자매 도시 (APIO20_swap)	C++17	0 / 100	2051 ms	15204 KiB

swap

#include "swap.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>

typedef long long llong;
const int MAXN = 100000 + 10;
const int INF  = 1e9;

int n, m;
bool vis[MAXN];
std::vector <std::pair <int,int>> g[MAXN];

bool dfs(int node, int par, int dist)
{
    bool res = false;
    vis[node] = true;

    for (const auto &[u, d] : g[node])
    {
        if (d > dist) continue;
        if (u == par)
        {
            continue;
        }

        if (vis[u])
        {
            res = true;
            continue;
        }

        res |= dfs(u, node, dist);
    }

    return res;
}

bool check(int u, int v, int dist)
{
    std::fill(vis + 1, vis + 1 + n, false);
    bool cycle = dfs(u, 0, dist);
    return cycle && vis[v];
}

void init(int N, int M, std::vector<int> U, std::vector<int> V, std::vector<int> W) 
{
    n = N; m = M;
    for (int i = 0 ; i < M ; ++i)
    {
        U[i]++; V[i]++;
        g[U[i]].emplace_back(V[i], W[i]);
        g[V[i]].emplace_back(U[i], W[i]);
    }
}

int getMinimumFuelCapacity(int x, int y) 
{
    x++; y++;
    int l = 0, r = INF + 1, mid;
    while (l < r - 1)
    {
        mid = (l + r) / 2;
        if (!check(x, y, mid)) l = mid;
        else r = mid;
    }

    if (r > INF) return -1;
    return r;
}

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• Subtask 6: 0 / 27