题解 | #游游的元素修改#

#include <iostream>
#include <queue>
#include <map>
#include <set>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <iomanip>
#include <stack>
#include <numeric>
#include <ctime>
#include <string>
#include <bitset>
#include <unordered_map>
#include <unordered_set>

using namespace std;
using ll = long long;

const ll N = 7e2 + 5, mod = 1e9 + 7, inf = 2e18;
const double esp = 1e-8;

ll n, l, r, ai, sum;

void solve() {
    cin >> n >> l >> r;
    ll L = 0, R = 0;
    sum=0;
    for (int i = 1; i <= n; i++) {
        cin >> ai;
        sum += ai;
        if (ai < l) {
            L += l - ai;
        }
        if (ai > r) {
            R += ai - r;
        }
    }

    if (sum / n >= l && ceil(sum*1.0/ n) <= r) {
        cout << max(L, R) << '\n';
        return ;
    }
    cout << -1 << '\n';
}

int main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    int t = 1;
    cin >> t;

    while (t--) {

        solve();

    }

    return 0;
}