공격적인 소 더블릿 (Aggressive Cow)

#include <stdio.h>
#include <algorithm>
#define INF 1e9
 
using namespace std;
 
int arr[100001] = { 0 };
 
int main() {
    int n, c;
    scanf("%d %d", &n, &c);
 
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }
    sort(arr, arr + n);    
 
    int left = 0, right = INF;
    int st = arr[0],tmp=1,mid;
    while (left+1 < right) {
        mid = (left + right) / 2;        
        for (int i = 0; i < n; i++) {
            if (arr[i] - st>=mid) {
                tmp++;
                st = arr[i];
            }
        }
        
        if (tmp >= c)             
            left = mid;        
        else 
            right = mid;        
        
        tmp = 1;
        st = arr[0];
    }
    printf("%d", left);
}