백준 2512번: 예산

https://www.acmicpc.net/problem/2512

1. 문제

2. 알고리즘

키워드 - 이분탐색, 구현

3. 코드

#include <iostream>
#include <sstream>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <list>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <stack>
#include <cstring>
 
using namespace std;
 
#define MAX_SIZE 100
#define INF 0x7fffffff
#define CENDL "\n"
#define ll long long
 
int main() {
 
    std::ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
 
    int n; cin >> n;
 
    vector<int> arr(n);
    int max_num = 0;
    for(int i=0; i<n; i++) {
        cin >> arr[i];
        max_num = max(arr[i], max_num);
    }
 
    int sum_num; cin >> sum_num;
    
    int start = 0;
    int end = max_num;
    int sum = 0;
 
    while (start <= end) {
        int middle = (start + end) / 2;
        sum = 0;
 
        for (int i=0; i<n; i++) {
            sum += min(arr[i], middle);
        }
 
        if(sum > sum_num) {
            end = middle - 1;
        } else {
            start = middle + 1;
        }
    }
 
    cout << end << CENDL;
 
    return 0;
}