题解 | #数字在升序数组中出现的次数#

java整数二分两个模板
1.将集合划分为[l,mid][mid + 1,r]
2.将集合划分为[l,mid - 1][mid,r]

public class Solution {
    public int GetNumberOfK(int [] array , int k) {
       if(array.length == 0) return 0;
       int l = 0, r = array.length - 1;
       while(l < r){
           int mid = l + r >> 1;
           if(array[mid] >= k) r = mid;
           else l = mid + 1;
       }
        int p = l;
        if(array[l] != k) return 0;
        l = 0;
        r = array.length - 1;
        while(l < r){
            int mid = l + r + 1 >> 1;
            if(array[mid] <= k) l = mid;
            else r = mid - 1;
        }
        return l - p + 1;
    }
}