Submission #221636

#	Time	Username	Problem	Language	Result	Execution time	Memory
221636		MKopchev	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	122 ms	3448 KiB

merchant

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

const int nmax=1e2+5,kmax=1e3+5,inf=1e9+42;

int n,m,k;

int cost[2][nmax][kmax];

int dist[nmax][nmax];

int max_gain[nmax][nmax];

long long current_edges[nmax][nmax],current_dists[nmax][nmax];

bool can(int test)
{
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
        {
            current_edges[i][j]=max_gain[i][j]-1LL*test*dist[i][j];
            current_dists[i][j]=current_edges[i][j];
        }

    for(int p=1;p<=n;p++)
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
                current_dists[i][j]=max(current_dists[i][j],current_dists[i][p]+current_dists[p][j]);

    for(int i=1;i<=n;i++)
        if(current_dists[i][i]>=0)return 1;
    return 0;
}
int main()
{
    scanf("%i%i%i",&n,&m,&k);

    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            dist[i][j]=inf;

    for(int i=1;i<=n;i++)
        for(int j=1;j<=k;j++)
            for(int t=0;t<2;t++)
                scanf("%i",&cost[t][i][j]);

    int u,v,c;

    for(int i=1;i<=m;i++)
    {
        scanf("%i%i%i",&u,&v,&c);
        dist[u][v]=min(dist[u][v],c);
    }

    for(int p=1;p<=n;p++)
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
                dist[i][j]=min(dist[i][j],dist[i][p]+dist[p][j]);

    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            if(dist[i][j]!=inf)
            {
                for(int p=1;p<=k;p++)
                    if(cost[0][i][p]!=-1&&cost[1][j][p]!=-1)max_gain[i][j]=max(max_gain[i][j],cost[1][j][p]-cost[0][i][p]);
            }


    int ok=0,not_ok=inf;

    while(not_ok-ok>1)
    {
        int av=(ok+not_ok)/2;
        if(can(av))ok=av;
        else not_ok=av;
    }

    printf("%i\n",ok);
    return 0;
}

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:36:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%i%i%i",&n,&m,&k);
     ~~~~~^~~~~~~~~~~~~~~~~~~
merchant.cpp:45:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
                 scanf("%i",&cost[t][i][j]);
                 ~~~~~^~~~~~~~~~~~~~~~~~~~~
merchant.cpp:51:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%i%i%i",&u,&v,&c);
         ~~~~~^~~~~~~~~~~~~~~~~~~

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