백준 1205번: 등수 구하기

https://www.acmicpc.net/problem/1205

1. 문제

2. 알고리즘

키워드 - 구현, 이분 탐색

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 <math.h>
#include <memory.h>
using namespace std;
 
#define MAX_SIZE 100
#define InF 0x7fffffff
#define CEnDL "\n"
#define ll long long
 
int main() {
 
    cin.tie(0);
    std::ios::sync_with_stdio(false);
 
    int n, score, size; cin >> n >> score >> size;
 
    vector<int> arr(n);
    for (int i=0; i<n; i++) {
        int d; cin >> d;
        arr[i] = -d;
    }
 
    if (n == 0) {
        cout << 1 << CEnDL;
        return 0;
    }
 
    int num = lower_bound(arr.begin(), arr.end(), -score)-arr.begin();
    if (-score == arr.back() && n == size)
        cout << -1;
    else
        cout << (num + 1 > size ? -1 : num + 1);
 
    return 0;
}