题解 | 分苹果

#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int>ai(n, 0);
    int sum = 0;
    for (int i = 0; i < n; i++) {
        cin >> ai[i];
        sum ++ ;
    }
    int nums = 0;
    bool isSolve = false;
    //cout << sum << endl;
    //cout << n << endl;
    if (sum % n != 0 ) {
        nums = -1;
        cout << nums << endl;
        return 0;
    }
    sort(ai.begin(), ai.end());

    while (ai[n - 1] > ( ai[0] + 2)) {
        ai[0] += 2;
        ai[n - 1] -= 2;
        sort(ai.begin(), ai.end());
        nums ++;
    }
    if (ai[n - 1] == ai[0]) {
        cout << nums << endl;
    } else {
        cout << -1 << endl;
    }
    return 0;
}
// 64 位输出请用 printf("%lld")