Submission #1166641

#	Time	Username	Problem	Language	Result	Execution time	Memory
1166641		SmuggingSpun	Travelling Merchant (APIO17_merchant)	C++20	100 / 100	83 ms	1352 KiB

merchant

#include<bits/stdc++.h>
#define taskname "B"
using namespace std;
typedef long long ll;
template<class T>void minimize(T& a, T b){
    if(a > b){
        a = b;
    }
}
template<class T>void maximize(T& a, T b){
    if(a < b){
        a = b;
    }
}
const ll INF = 1e18;
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
    int n, m, k;
    cin >> n >> m >> k;
    vector<vector<int>>buy(n + 1, vector<int>(k + 1)), sell(n + 1, vector<int>(k + 1));
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= k; j++){
            cin >> buy[i][j] >> sell[i][j];
        }
    }
    auto floyd_warshall = [&] (vector<vector<ll>>& g){
        for(int k = 1; k <= n; k++){
            for(int u = 1; u <= n; u++){
                for(int v = 1; v <= n; v++){
                    minimize(g[u][v], g[u][k] + g[k][v]);
                }
            }
        }
    };
    vector<vector<ll>>g(n + 1, vector<ll>(n + 1, INF)), g2 = g;
    for(int i = 0; i < m; i++){
        int u, v;
        cin >> u >> v >> g[u][v];
    }
    floyd_warshall(g);
    vector<vector<int>>profit(n + 1, vector<int>(n + 1, 0));
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= n; j++){
            for(int t = 1; t <= k; t++){
                if(buy[i][t] != -1 && sell[j][t] != -1){
                    maximize(profit[i][j], sell[j][t] - buy[i][t]);
                }
            }
        }
    }
    int low = 1, high = 1e9, ans = 0;
    while(low <= high){
        int mid = (low + high) >> 1;
        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= n; j++){
                g2[i][j] = ll(mid) * min(g[i][j], INF / mid) - profit[i][j];
            }
        }
        floyd_warshall(g2);
        bool flag = false;
        for(int i = 1; i <= n; i++){
            if(g2[i][i] < 1){
                flag = true;
                break;
            }
        }
        if(flag){
            low = (ans = mid) + 1;
        }
        else{
            high = mid - 1;
        }
    }
    cout << ans;
}

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:19:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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