백준 16564번 히오스 프로게이머 C++

https://www.acmicpc.net/problem/16564

16564번: 히오스 프로게이머

 

이분탐색

 

#include <iostream>
#include <string>
#include <vector>
#include <math.h>
#include <algorithm>
#include <utility>
#include <stack>
#include <queue>
#include <math.h>
#include <set>
#include <map>
#include <list>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <limits.h>

using namespace std;
using int64 = long long;

int n;
int64 k;
vector<int> v;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    cin >> n >> k;
    v = vector<int>(n);
    for (int i = 0; i < n; i++) {
        cin >> v[i];
    }
    int left = 1;
    int right = 1000000001;
    int ans = 0;
    while (left <= right) {
        int mid = (left + right) / 2;

        int64 sum = 0;
        for (int i = 0; i < n; i++) {
            if (v[i] < mid) {
                sum += mid - v[i];
            }
        }
        
        if (k < sum) {
            right = mid - 1;
        }
        else {
            ans = mid;
            left = mid + 1;
        }
    }
    cout << ans;
}