Submission #492514

#	Time	Username	Problem	Language	Result	Execution time	Memory
492514		Mahfel	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	99 ms	4344 KiB

merchant

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll MXN = 120 , MXM = 10000 , MXK = 1020 , Inf = 1e10;
ll n,m,k;
ll profit[MXN][MXN] , dis[MXN][MXN];
ll buy[MXN][MXK] , sell[MXN][MXK];
ll gr[MXN][MXN];
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
 
    cin >> n >> m >> k;
    for(int i = 1 ; i <= n ; i++) {
        for(int j = 1 ; j <= k ; j++) {
            cin >> buy[i][j] >> sell[i][j];
            // if(buy[i][j] == -1) buy[i][j] = Inf;
            // if(sell[i][j] == -1) sell[i][j] = -Inf;
        }
    }
 
    for(int i = 1 ; i <= n ; i++) {
        for(int j = 1 ; j <= n ; j++) {
            dis[i][j] = Inf;
        }
        dis[i][i] = 0;
    }
    for(int i = 0 ; i < m ; i++) {
        ll v,u,w; cin >> v >> u >> w;
        dis[v][u] = w;
    }
    for(int k = 1 ; k <= n ; k++) {
        for(int i = 1 ; i <= n ; i++) {
            for(int j = 1 ; j <= n ; j++) {
                dis[i][j] = min(dis[i][j] , dis[i][k] + dis[k][j]);
            }
        }
    }
 
    for(int i = 1 ; i <= n ; i++) {
        for(int j = 1 ; j <= n ; j++) {
            for(int x = 1 ; x <= k ; x++) {
                if(sell[j][x] != -1 && buy[i][x] != -1) profit[i][j] = max(profit[i][j] , sell[j][x] - buy[i][x]);
            }
        }
    }

    ll l = 0 , r = 1000000000 + 200;
    while(r-l > 1) {
        ll m = (l+r)/2;
        for(int i = 1 ; i <= n ; i++) {
            for(int j = 1 ; j <= n ; j++) {
                gr[i][j] = dis[i][j]*m - profit[i][j];
            }
            gr[i][i] = Inf;
        }
        for(int k = 1 ; k <= n ; k++) {
            for(int i = 1 ; i <= n ; i++) {
                for(int j = 1 ; j <= n ; j++) {
                    if(gr[i][k] < Inf) gr[i][j] = min(gr[i][j] , gr[i][k] + gr[k][j]);
                    // if(gr[i][k] + gr[k][j] < gr[i][j]-EPS) {
                    //     gr[i][j] = gr[i][k] + gr[k][j];
                    // }
                    // if(gr[i][j] < -Inf) gr[i][j] = -Inf;
                }
            }
        }
        bool ok = 0;
        for(int i = 1 ; i <= n ; i++) {
            if(gr[i][i] <= 0) {
                ok = 1; break;
            }
        }
        if(ok) {
            l = m;
        } else {
            r = m;
        }
    }
    
    cout << l << "\n";
    // printf("%.0lf\n" , l);
}

• Subtask 1: 12 / 12
• Subtask 2: 21 / 21
• Subtask 3: 33 / 33
• Subtask 4: 34 / 34