用二分查找查询某一个数出现的次数

#include<iostream>
#include<algorithm>
using namespace std;
int arr[1003];
int main()
{
    int n,k;
    cin>>n>>k;//n个数，查找k出现的次数 
    for(int i=0;i<n;i++){
        cin>>arr[i];
    }
    sort(arr,arr+n);
    int low=0;
    int high=n-1,mid;
    while(low<=high){
        mid=(high-low)/2+low;
        if(arr[mid]>k) high=mid;
        else if(arr[mid]<k) low=mid;
        else {
            if(arr[mid-1]==k&&mid>=0)
                high=mid;
            else 
                break;    
        }
    }
    low=0,high=n-1;
    int mid1;
    while(low<=high){
        mid1=(high-low)/2+low;
        if(arr[mid1]>k) high=mid1;
        else if(arr[mid1]<k) low=mid1;
        else {
            if(arr[mid1+1]==k&&mid1<n-1)
                low=mid1;
            else 
                break;    
        }
    }
    cout<<mid1-mid+1<<endl;
    return 0;
}