Establish equality

#include <bits/stdc++.h>
#define fast ios::sync_with_stdio(0); cin.tie(0);
#define fill(arr,val) memset(arr,val,sizeof(arr))
#define FOR(i, a, b) for(__typeof(b) i = a, _b = b; i <= _b; ++i)
#define FORD(i, a, b) for(__typeof(a) i = a, _b = b; i >= _b; --i)
#define ALL(a) (a).begin(), (a).end()
#define YES cout << "YES\n"
#define NO cout << "NO\n"
#define ll long long
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define ii pair<int,int>
#define iii pair<int,pair<int,int>>
#define dq deque<int>
#define nend '\n'
using namespace std;
const ll hashi=2e9+11;
ll add(ll a, ll b) {
    return (a+b)%hashi;
}
ll sub(ll a, ll b) {
    return ((a-b)%hashi+hashi)%hashi;
}
ll mul(ll a, ll b) {
    return (a*b)%hashi;
}
const ll inf=1e18;
const int dx[]={1,0,-1,0};
const int dy[]={0,1,0,-1};
const int N=2e5+3;

int n;
ll b[N];
ll pre[N];
ll S;

bool feasible(ll x) {
    int idx = lower_bound(b+1, b+n+1, x) - b;
    idx--;
    ll cnt = idx;
    ll sum = pre[idx];
    ll B = x*cnt - sum;
    return B + (ll)n*x <= S;
}

int main() {
    fast;
    cin >> n;
    FOR(i,1,n) cin >> b[i];
    sort(b+1, b+n+1);
    pre[0] = 0;
    FOR(i,1,n) pre[i] = pre[i-1] + b[i];
    S = pre[n];

    ll lo = 0, hi = b[n];
    ll ans = 0;
    while (lo <= hi) {
        ll mid = lo + (hi-lo)/2;
        if (feasible(mid)) {
            ans = mid;
            lo = mid+1;
        } else {
            hi = mid-1;
        }
    }
    cout << ans << nend;
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: WRONG ANSWER

Test 30

Verdict: ACCEPTED

Test 31

Verdict: WRONG ANSWER

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: WRONG ANSWER

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: WRONG ANSWER

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: WRONG ANSWER

Test 50

Verdict: ACCEPTED

Test 51

Verdict: WRONG ANSWER

Test 52

Verdict: ACCEPTED

Test 53

Verdict: ACCEPTED

Test 54

Verdict: ACCEPTED

Test 55

Verdict: WRONG ANSWER