题解 | AOE还是单体？

#include <bits/stdc++.h>
using namespace std;
#define int long long

int n, x;

int calc(const vector<int> &arr, int m)
{
    int res = m * x;
    for (int i = 1; i <= n; ++i)
    {
        if (arr[i] > m)
        {
            res += arr[i] - m;
        }
    }
    return res;
}

signed main()
{
    cin >> n >> x;
    vector<int> arr(n + 1, 0);
    int max_num = 0; 
    for (int i = 1; i <= n; ++i)
    {
        cin >> arr[i];
        max_num = max(max_num, arr[i]);
    }

    int l = 0, r = max_num;
    int ans = LLONG_MAX;

    while (l <= r)
    {
        int mid = (l + r) / 2;
        int val_mid = calc(arr, mid);
        ans = min(ans, val_mid);

        int val_next = calc(arr, mid + 1);
        if (val_mid < val_next)
        {
           
            r = mid - 1;
        }
        else
        {
            l = mid + 1;
        }
    }

    cout << ans << endl;
    return 0;
}