Submission #1199094

#	Time	Username	Problem	Language	Result	Execution time	Memory
1199094		Gray	Swapping Cities (APIO20_swap)	C++20	17 / 100	2094 ms	22600 KiB

swap

#include "swap.h"
#pragma GCC optimize("unroll-loops,Ofast")
#include <bits/stdc++.h>
#define ll int
#define ln "\n"
using namespace std;

ll n, m;
vector<array<ll, 3>> e;
vector<ll> enabled;
vector<vector<ll>> A;

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

void dfs(ll u, ll to, vector<ll> &vis, ll &cnt1, ll &cnt2, ll &apos, ll &req){
    vis[u]=1; cnt1++; ll cct=0; if (u==to) req=1;
    for (auto i:A[u]){
        ll v = e[i][0]^e[i][1]^u;
        if (!enabled[i]) continue;
        cnt2++; cct++;
        if (!vis[v]) dfs(v, to, vis, cnt1, cnt2, apos, req);
    }
    if (cct>=3) apos=1;
}

int getMinimumFuelCapacity(int X, int Y) {
    ll l=0, r=2e9; vector<ll> vis(n);
    while (l+1<r){
        ll mid = l+(r-l)/2;
        enabled.assign(m, 0); vis.assign(n, 0);
        for (ll i=0; i<m; i++){
            if (e[i][2]<=mid) enabled[i]=1;
        }
        vis.assign(n, 0); ll cnt1=0, cnt2=0, pos1=0, pos2=0;
        dfs(X, Y, vis, cnt1, cnt2, pos1, pos2);
        if (pos2 and (pos1 or (cnt2/2>=cnt1))){
            r=mid;
        }else l=mid;
    }
    return (r==2e9?-1:r);
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 7
• Subtask 3: 17 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27