1295. Find Numbers with Even Number of Digits #

Problem #

Given an array nums of integers, return how many of them contain an even number of digits.

Example 1:

Input: nums = [12,345,2,6,7896]
Output: 2
Explanation: 
12 contains 2 digits (even number of digits). 
345 contains 3 digits (odd number of digits). 
2 contains 1 digit (odd number of digits). 
6 contains 1 digit (odd number of digits). 
7896 contains 4 digits (even number of digits). 
Therefore only 12 and 7896 contain an even number of digits.

Example 2:

Input: nums = [555,901,482,1771]
Output: 1 
Explanation: 
Only 1771 contains an even number of digits.

Constraints:

• 1 <= nums.length <= 500
• 1 <= nums[i] <= 10^5

Problem Summary #

Given an integer array nums, return the number of numbers whose number of digits is even.

Constraints:

• 1 <= nums.length <= 500
• 1 <= nums[i] <= 10^5

Solution Approach #

• Given an integer array, output the number of numbers whose number of digits is even.
• A simple problem: convert each number to a string and check whether its length is even.

Code #

func findNumbers(nums []int) int {
	res := 0
	for _, n := range nums {
		res += 1 - len(strconv.Itoa(n))%2
	}
	return res
}