2529. Maximum Count of Positive Integer and Negative Integer

题目 #

Given an array nums sorted in non-decreasing order, return the maximum between the number of positive integers and the number of negative integers.

  • In other words, if the number of positive integers in nums is pos and the number of negative integers is neg, then return the maximum of pos and neg.

Note that 0 is neither positive nor negative.

Example 1:

Input: nums = [-2,-1,-1,1,2,3]
Output: 3
Explanation: There are 3 positive integers and 3 negative integers. The maximum count among them is 3.

Example 2:

Input: nums = [-3,-2,-1,0,0,1,2]
Output: 3
Explanation: There are 2 positive integers and 3 negative integers. The maximum count among them is 3.

Example 3:

Input: nums = [5,20,66,1314]
Output: 4
Explanation: There are 4 positive integers and 0 negative integers. The maximum count among them is 4.

Constraints:

  • 1 <= nums.length <= 2000
  • -2000 <= nums[i] <= 2000
  • nums is sorted in a non-decreasing order.

思路1 两次二分 #

分析 #

  • 给的数组排好序了，二分查一下第一个0，再对剩下的二分查一下第一个正数

代码 # 

 1func maximumCount(nums []int) int {
 2	neg := sort.Search(len(nums), func(i int) bool {
 3		return nums[i] >= 0
 4	})
 5	pos := sort.Search(len(nums)-neg, func(i int) bool {
 6		return nums[i+neg] > 0
 7	}) + neg
 8	if neg < len(nums)-pos {
 9		return len(nums) - pos
10	}
11	return neg
12}