giúp mình vs ạ

cần rất gấp

#include <iostream>
#define fi "BANH.INP"
#define fo "BANH.OUT"
using namespace std;
int n, m, k;
int main() 
{
    freopen(fi, "r", stdin);
    freopen(fo, "w", stdout);
    cin >> m >> n >> k;
    if(m >= k) cout <<(int) m*n*80/100;
    else
    {
        if(int(k*n*80/100) < int(m*n)) cout << int(k*n*80/100);
        else cout << int(m*n*80/100);
    }
    return 0;
}

$#khanhtaon$

#include <iostream>
#include <fstream>
using namespace std;

int min_cost(int n, int m, int k) {
    if (n < k) {
        return n * m;
    } else {
        return (n / k) * k * m * 0.8 + (n % k) * m;
    }
}

int main() {
    ifstream inFile("BAI1.INP");
    ofstream outFile("BAI1.OUT");
    
    int n, m, k;
    inFile >> n >> m >> k;
    
    int cost = min_cost(n, m, k);
    
    outFile << static_cast<int>(cost);
    
    inFile.close();
    outFile.close();
    
    return 0;
}