逻辑看注释
#include<iostream>
using namespace std;
int money = 10001,n,list[2][3],moneys[3];
int main(){
cin>>n;
cin>>list[0][0]>>list[1][0];
cin>>list[0][1]>>list[1][1];
cin>>list[0][2]>>list[1][2];
for(int i = 0;i < 3;++i){
int count = 0,j = 0;
while(count < n){
++j;
count += list[0][i];
}
moneys[i] = j * list[1][i];
}
for(int i = 0;i < 3;++i){
money = min(money,moneys[i]);
}
cout<<money;
return 0;
}