Submission #52095

#	Time	Username	Problem	Language	Result	Execution time	Memory
52095		Angelos	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	404 ms	1852 KiB

merchant

#include <iostream>
#include <cstring>
#define MAXN 103
#define MAXK 1003
const long long INF = 1e10;
using namespace std;
typedef long long ll;
int N , M , K , T[MAXN][MAXN] , B[MAXN][MAXK] , S[MAXN][MAXK];
long long profit[MAXN][MAXN] , adj[MAXN][MAXN] , adj2[MAXN][MAXN]  , dist[MAXN][MAXN];

bool check(ll x){
    for(int i=1; i<=N; i++){
        for(int j=1; j<=N; j++){
            if(i == j || dist[i][j] == INF){adj[i][j] = -INF; continue;}
            adj[i][j] = (ll)profit[i][j] - (ll)dist[i][j]*x;
            adj[i][j] = max(-INF, adj[i][j]);
        }
    }



    for(int k=1; k<=N; k++)
        for(int i=1; i<=N; i++)
            for(int j=1; j<=N; j++){
                adj[i][j] = max(adj[i][j] , adj[i][k] + adj[k][j]);

                if(adj[i][i] >= 0) return true;

                adj[i][j] = min(INF , adj[i][j]);
                adj2[i][j] = adj[i][j];
            }


    /*cout << endl;

    for(int i=1; i<=N; i++){
        for(int j=1; j<=N; j++)
            cout << adj[i][j] << " " ;
        cout << endl;
    }

    cout << endl;*/

    for(int k=1; k<=N; k++)
        for(int i=1; i<=N; i++)
            for(int j=1; j<=N; j++){
                adj2[i][j] = max(adj2[i][j] , adj2[i][k] + adj2[k][j]);
                if(adj2[i][j] > adj[i][j]) return true;
            }

    return false;
}

int main(){
    cin >> N >> M >> K;


    for(int i=1; i<=N; i++)
        for(int k=0; k<K; k++)  cin >> B[i][k] >> S[i][k];


    for(int i=0; i<=N; i++)
        for(int j=0; j<=N; j++) dist[i][j] = INF;

    for(int i=1; i<=N; i++)    dist[i][i] = 0;

    for(int i=0; i<M; i++){
        int u,v;
        ll w; cin >> u >> v >> w;

        dist[u][v] = min(dist[u][v] , w);
    }



    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++){
            profit[i][j] = 0;
            for(int k=0; k<K; k++){
                if(B[i][k] == -1 || S[j][k] == -1) continue;
                profit[i][j] = max(profit[i][j] , (ll)S[j][k] - (ll)B[i][k]);
            }
        }


    /*for(int i=1; i<=N; i++){
        for(int j=1; j<=N; j++)
            cout << dist[i][j] << " " ;
        cout << endl;
    }*/

    long long low = 1 , high = 1e9 + 1 , ANS = 0;


    while(low <= high){
        ll mid = (low + high)/2;

        //cout << low << " " << mid << " " << high << endl;

        if(check(mid)) {ANS = max(ANS , mid); low = mid + 1;}
        else    high = mid - 1;
    }

    cout << ANS << endl;



    return 0;
}

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