NC74 数字在升序数组中出现的次数

二分查找 还写了半天。
right = mid-1 我直接写成了 right= mid。
还要考虑没有查找到的情况

public class Solution {
    public int GetNumberOfK(int [] array , int k) {
        int len = array.length;
        if(len ==0) return 0;
        int mid = -1;
        int left = 0;
        int right = len-1;
        while(left<=right){
            mid = (left + right) /2;
            if(array[mid] > k){
                right = mid-1;
            }
            else if( array[mid] < k){
                left = mid+1;
            }
            else break;
        }
        if(array[mid]!=k){return 0;}

        while(mid>0 && array[mid] == array[mid-1]){mid--;}

        int res = 1;
        while(mid+1<array.length && array[mid] == array[mid+1]){mid++;res++;}

        return res;
    }
}