Submission #978828

#	Time	Username	Problem	Language	Result	Execution time	Memory
978828		nnin	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	78 ms	4268 KiB

merchant

#include<bits/stdc++.h>
using namespace std;
#define ll long long
 
int N, M, K;
ll B[105][1005], S[105][1005], mindis[105][105], profit[105][105], mat[105][105];
 
bool check(ll x) {
    for(int i=1;i<=N;i++) for(int j=1;j<=N;j++) {
        if(mindis[i][j]==1e13 || i==j) mat[i][j] = -1e13;
        else mat[i][j] = profit[i][j]-(x*mindis[i][j]);
    }
    for(int k=1;k<=N;k++) for(int i=1;i<=N;i++) for(int j=1;j<=N;j++) {
        mat[i][j] = max(mat[i][j], mat[i][k]+mat[k][j]);
    }
    for(int i=1;i<=N;i++) {
        if(mat[i][i]>=0) return true;
    }
    return false;
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    cin>>N>>M>>K;
    for(int i=1;i<=N;i++) for(int j=1;j<=K;j++) cin>>B[i][j]>>S[i][j];
    for(int i=1;i<=N;i++) {
        for(int j=1;j<=N;j++) mindis[i][j] = 1e13;
        mindis[i][i] = 0;
    }
    while(M--) {
        int u, v; ll w;
        cin>>u>>v>>w;
        mindis[u][v] = w;
    }
    for(int k=1;k<=N;k++) for(int i=1;i<=N;i++) for(int j=1;j<=N;j++) {
        mindis[i][j] = min(mindis[i][j], mindis[i][k]+mindis[k][j]);
    }
    for(int i=1;i<=N;i++) for(int j=1;j<=N;j++) {
        if(i==j) continue;
        profit[i][j] = 0;
        for(int k=1;k<=K;k++) {
            if(B[i][k]==-1 || S[j][k]==-1) continue;
            profit[i][j] = max(profit[i][j], S[j][k]-B[i][k]);
        }
    }
    ll l = 0, r = 1e9;
    while(l<r) {
        ll m = (l+r+1)/2;
        if(check(m)) l = m;
        else r = m-1;
    }
    cout<<l;
}

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