题解 | #数字在升序数组中出现的次数#

package main

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 *
 * @param nums int整型一维数组
 * @param k int整型
 * @return int整型
 */
func GetNumberOfK(nums []int, k int) int {
	// write code here
	l := binarySearch(nums, k)
	r := binarySearch(nums, k+1)
	if l == len(nums) || nums[l] != k {
		return 0
	}

	return r - l
}

func binarySearch(nums []int, k int) int {
	l, r := 0, len(nums)
	for l < r {
		mid := (r-l)/2 + l
		if nums[mid] >= k {
			r = mid

			continue
		}
		l = mid + 1
	}

	return l
}