package com.company;

import org.junit.Test;

public class GetNumberOfK {

//统计一个数字在排序数组中出现的次数。

public int GetNumberOfK(int[] array, int k) {

if (array == null || array.length == 0) return 0;

int left = 0;

int right = array.length - 1;

int mid = (left + right) / 2;

int count = 0;

if (left - right == 0 && array[left] == k) return 1;

while (left <= mid - 1 || right >= mid + 1) {

mid = (left + right) / 2;

if (array[mid] < k) {

left = mid + 1;

}

if (array[mid] > k) {

right = mid - 1;

}

if (array[mid] == k) {

++count;

while (left <= mid - 1 || right >= mid + 1) {

if (left <= mid - 1 && array[left] == k) ++count;

if (right >= mid + 1 && array[right] == k) ++count;

left++;

right--;

}

break;

}

}

return count;

}

@Test

public void test() {

System.out.println(GetNumberOfK(new int[]{3, 3}, 3));

}

}