Submission #487986

#	Time	Username	Problem	Language	Result	Execution time	Memory
487986		Mahfel	Travelling Merchant (APIO17_merchant)	C++17	0 / 100	122 ms	2204 KiB

merchant

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll MXN = 120 , MXM = 10000 , MXK = 1020 , Inf = 1e15 + 7;
ll n,m,k;
ll profit[MXN][MXN] , dis[MXN][MXN];
ll buy[MXN][MXK] , sell[MXN][MXK];
double 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++) {
                profit[i][j] = max(profit[i][j] , sell[j][x] - buy[i][x]);
            }
        }
    }

    // for(int i = 1 ; i <= n ; i++) {
    //     for(int j = 1 ; j <= n ; j++) {
    //         cout << "(" << profit[i][j] << "," << dis[i][j] << ") ";
    //     }
    //     cout << "\n";
    // }

    double l = 0 , r = 1000000000000;
    for(int itr = 0 ; itr < 100 ; itr++) {
        double m = (l+r)/2.0;
        for(int i = 1 ; i <= n ; i++) {
            for(int j = 1 ; j <= n ; j++) {
                gr[i][j] = double(dis[i][j])*m - double(profit[i][j]);
                if(i == j) gr[i][j] = 0;
            }
        }
        for(int k = 1 ; k <= n ; k++) {
            for(int i = 1 ; i <= n ; i++) {
                for(int j = 1 ; j <= n ; j++) {
                    gr[i][j] = min(gr[i][j] , gr[i][k] + gr[k][j]);
                }
            }
        }
        bool ok = 0;
        for(int i = 1 ; i <= n ; i++) {
            // cout << i << ": " << gr[i][i] << "\n";
            if(gr[i][i] < 0) {
                ok = 1; break;
            }
        }
        if(ok) {
            l = m;
            // ans = "YES\n";
        } else {
            r = m;
            // ans = "NO\n";
        }
    }
    
    printf("%.0lf\n" , l);
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 21
• Subtask 3: 0 / 33
• Subtask 4: 0 / 34