Submission #309922

#	Time	Username	Problem	Language	Result	Execution time	Memory
309922		vipghn2003	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	135 ms	2296 KiB

merchant

#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define fi first
#define se second
#define mp make_pair
using namespace std;

const int N=105;
const int K=1005;
int n,m,k,d[N][N],buy[N][K],sell[N][K],opt[N][N],w[N][N];

bool check(int lim)
{
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++)
        {
            w[i][j]=-3e18;
            if(d[i][j]==3e18) continue;
            int dist=d[i][j];
            int gain=opt[i][j];
            w[i][j]=gain-dist*lim;
        }
    }
    for(int k=1;k<=n;k++)
    {
        for(int i=1;i<=n;i++)
        {
            for(int j=1;j<=n;j++)
            {
                w[i][j]=max(w[i][j],w[i][k]+w[k][j]);
                if(w[i][j]>=3e18) w[i][j]=3e18;
            }
        }
    }
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++) if(w[i][j]+w[j][i]>=0) return true;
    }
    return false;
}

main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    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=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++) d[i][j]=3e18;
    }
    while(m--)
    {
        int u,v,w;
        cin>>u>>v>>w;
        d[u][v]=w;
    }
    for(int u=1;u<=n;u++)
    {
        for(int i=1;i<=n;i++)
        {
            for(int j=1;j<=n;j++)
            {
                int val=d[i][u]+d[u][j];
                d[i][j]=min(d[i][j],val);
            }
        }
    }
    for(int u=1;u<=n;u++)
    {
        for(int v=1;v<=n;v++)
        {
            opt[u][v]=0;
            for(int item=1;item<=k;item++)
            {
                if(buy[u][item]==-1||sell[v][item]==-1) continue;
                opt[u][v]=max(opt[u][v],sell[v][item]-buy[u][item]);
            }
        }
    }
    int l=1,r=1e9,res=0;
    while(l<=r)
    {
        int mid=(l+r)/2;
        if(check(mid))
        {
            res=mid;
            l=mid+1;
        }
        else r=mid-1;
    }
    cout<<res;
}

Compilation message (stderr)

merchant.cpp:44:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   44 | main()
      |      ^

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