Submission #945037

#	Time	Username	Problem	Language	Result	Execution time	Memory
945037		JakobZorz	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	77 ms	4252 KiB

merchant

#include<iostream>
#include<vector>
#include<queue>
#include<stack>
#include<algorithm>
#include<limits.h>
#include<math.h>
#include<map>
#include<set>
#include<unordered_map>
#include<unordered_set>
#include<iomanip>
#include<cstring>
#include<random>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
using namespace std;

int n,m,k;
ll buy[100][1000];
ll sell[100][1000];
ll profit[100][100];
ll dist[100][100];
ll cost[100][100];

void solve(){
    cin>>n>>m>>k;
    for(int i=0;i<n;i++)
        for(int j=0;j<k;j++)
            cin>>buy[i][j]>>sell[i][j];
    for(int i1=0;i1<n;i1++)
        for(int i2=0;i2<n;i2++)
            for(int j=0;j<k;j++)
                if(sell[i2][j]!=-1&&buy[i1][j]!=-1)
                    profit[i1][i2]=max(profit[i1][i2],sell[i2][j]-buy[i1][j]);
    for(int i1=0;i1<n;i1++)
        for(int i2=0;i2<n;i2++)
            dist[i1][i2]=1e18;
    for(int i=0;i<m;i++){
        int a,b,w;
        cin>>a>>b>>w;
        dist[a-1][b-1]=w;
    }
    for(int j=0;j<n;j++)
        for(int i1=0;i1<n;i1++)
            for(int i2=0;i2<n;i2++)
                dist[i1][i2]=min(dist[i1][i2],dist[i1][j]+dist[j][i2]);
    ll l=0,r=2e9;
    while(l<r-1){
        ll curr=(l+r)/2;
        // does there exist a cycle with efficiency at least curr?
        for(int i1=0;i1<n;i1++)
            for(int i2=0;i2<n;i2++)
                cost[i1][i2]=curr*min(dist[i1][i2],ll(1e18)/curr)-profit[i1][i2];
        for(int j=0;j<n;j++)
            for(int i1=0;i1<n;i1++)
                for(int i2=0;i2<n;i2++)
                    cost[i1][i2]=min(cost[i1][i2],cost[i1][j]+cost[j][i2]);
        bool has=false;
        for(int i=0;i<n;i++)
            if(cost[i][i]<=0)
                has=true;
        if(has)
            l=curr;
        else
            r=curr;
    }
    cout<<l<<"\n";
}

int main(){
    ios::sync_with_stdio(false);cout.tie(NULL);cin.tie(NULL);
    //freopen("/Users/jakob/cp_testing/test.txt","r",stdin);freopen("output.out","w",stdout);
    int t=1;//cin>>t;
    while(t--)solve();
    return 0;
}


/*

4 5 2
10 9 5 2
6 4 20 15
9 7 10 9
-1 -1 16 11
1 2 3
2 3 3
1 4 1
4 3 1
3 1 1
 
 */

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