Submission #551338

#	Time	Username	Problem	Language	Result	Execution time	Memory
551338		nicholask	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	152 ms	4448 KiB

merchant

#include <bits/stdc++.h>
#define int long long
#define x first
#define y second
#define pb push_back
using namespace std;
using pii=pair <int,int>;
int n,m,k;
int buy[101][1001],sell[101][1001];
vector <pii> g[101];
int p[101][101],d[101][101],nw[101][101];
signed main(){
    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];
    }
    for (int i=0; i<m; i++){
        int u,v,w;
        cin>>u>>v>>w;
        g[u].pb({v,w});
    }
    for (int i=1; i<=n; i++){
        for (int j=1; j<=n; j++){
            p[i][j]=0;
            for (int l=1; l<=k; l++){
                if (buy[i][l]!=-1&&sell[j][l]!=-1) p[i][j]=max(p[i][j],-buy[i][l]+sell[j][l]);
            }
        }
    }
    for (int i=1; i<=n; i++){
        for (int j=1; j<=n; j++) d[i][j]=1e18;
        d[i][i]=0;
    }
    for (int i=1; i<=n; i++){
        for (auto j:g[i]) d[i][j.x]=min(d[i][j.x],j.y);
    }
    for (int l=1; l<=n; l++){
        for (int i=1; i<=n; i++){
            for (int j=1; j<=n; j++) d[i][j]=min(d[i][j],d[i][l]+d[l][j]);
        }
    }
    int l=0,r=2e9;
    while (l<r){
        int mid=(l+r+1)/2;
        for (int i=1; i<=n; i++){
            for (int j=1; j<=n; j++){
                if (i==j) nw[i][j]=-1e13;
                else if (d[i][j]!=1e18) nw[i][j]=p[i][j]-mid*d[i][j];
                else nw[i][j]=-1e13;
            }
        }
        for (int l=1; l<=n; l++){
            for (int i=1; i<=n; i++){
                for (int j=1; j<=n; j++) nw[i][j]=max(nw[i][j],nw[i][l]+nw[l][j]);
            }
        }
        bool found=0;
        for (int i=1; i<=n; i++){
            if (nw[i][i]>=0) found=1;
        }
        if (found) l=mid;
        else r=mid-1;
    }
    cout<<l<<'\n';
}

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