题解 | #数字在升序数组中出现的次数#

public class Solution {
    public int GetNumberOfK(int [] array , int k) {
        // 左闭右闭
        int left = 0;
        int right = array.length - 1;
        // 因为是闭区间 不加等于号会漏掉一个元素
        while (left <= right){
            int mid = left + (right - left)/2;
            if(array[mid] == k){
                while (array[left] != k || array[right] != k){
                    if (array[left] != k) left ++;
                    else right --;
                }
                return right - left + 1;

            }else if(array[mid] < k){
                left = mid + 1;
            }else{
                right = mid - 1;
            }
        }
        return 0;
    }
}