题解 | 买苹果

#include <iostream>
using namespace std;
const int N = 100 + 10;

int n, res, f[N];

int main() {
    cin >> n;
    for (int i = 0; i <= 7; i++ ) f[i] = N;
    f[6] = 1;
    f[8] = 1;
    if (n > 8) {
        for (int i = 9; i <= n; i++ ) {
            int t = min(f[i - 6], f[i - 8]);
            if (t != N )  f[i] = t + 1;
            else f[i] = N;
        }
    }
    res = f[n] != N ? f[n] : -1;
    cout << res << endl;
}