Submission #306209

#	Time	Username	Problem	Language	Result	Execution time	Memory
306209		jovan_b	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	960 ms	6288 KiB

merchant

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;

ll buy[105][1005];
ll sell[105][1005];

ll dist[1005][1005];
ll graf[1005][1005];
ll prof[1005][1005];
ld tren[1005][1005];

const ll INF = 1000000000000LL;

int n;

bool cmp(ld a, ld b){
    return abs(a-b) > 0.0001;
}

bool check(ld val){
    for(int i=1; i<=n; i++){
        for(int j=1; j<=n; j++){
            if(dist[i][j] == INF) tren[i][j] = INF;
            else tren[i][j] = - prof[i][j] + (1.0*dist[i][j])*val;
            //cout << i << " " << j << " " << tren[i][j] << endl;
        }
    }
    for(int k=1; k<=n; k++){
        for(int i=1; i<=n; i++){
            for(int j=1; j<=n; j++){
                tren[i][j] = min(tren[i][j], tren[i][k] + tren[k][j]);
            }
        }
    }
    for(int k=1; k<=n; k++){
        for(int i=1; i<=n; i++){
            for(int j=1; j<=n; j++){
                if(tren[i][j] > tren[i][k] + tren[k][j] && cmp(tren[i][j], tren[i][k] + tren[k][j])) return 1;
            }
        }
    }
    return 0;
}

int main(){
    ios_base::sync_with_stdio(false), cin.tie(0);
    cout.precision(10);
    cout << fixed;

    int m, K;
    cin >> n >> m >> K;
    for(int i=1; i<=n; i++){
        for(int j=1; j<=K; j++){
            cin >> buy[i][j];
            cin >> sell[i][j];
            //buy[i][j] *= 2;
            //sell[i][j] *= 2;
        }
    }
    for(int i=1; i<=n; i++){
        for(int j=1; j<=n; j++){
            dist[i][j] = graf[i][j] = INF;
        }
        dist[i][i] = graf[i][i] = 0;
    }
    for(int i=1; i<=m; i++){
        ll a, b, c;
        cin >> a >> b >> c;
        //c *= 2;
        dist[a][b] = graf[a][b] = min(graf[a][b], c);
    }
    for(int k=1; k<=n; k++){
        for(int i=1; i<=n; i++){
            for(int j=1; j<=n; j++){
                dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
            }
        }
    }
    for(int i=1; i<=n; i++){
        for(int j=1; j<=n; j++){
            if(i == j) continue;
            for(int k=1; k<=K; k++){
                if(buy[i][k]+1 && sell[j][k]+1) prof[i][j] = max(prof[i][j], sell[j][k]-buy[i][k]);
            }
            //cout << i << " " << j << " za " << prof[i][j] << endl;
        }
    }
    ld res = 0, l = 1, r = 1000000000;
    int tries = 80;
    while(tries--){
        ld mid = (l+r)/2;
        if(check(mid)){
            res = mid;
            l = mid;
        }
        else r = mid;
    }
    res += 0.001;
    ll rr = res;
    cout << rr << "\n";
    return 0;
}

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