main.go

// Source: https://leetcode.com/problems/find-numbers-with-even-number-of-digits
// Title: Find Numbers with Even Number of Digits
// Difficulty: Easy
// Author: Mu Yang <http://muyang.pro>

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// 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`
//
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

package main

import (
	"math"
)

func findNumbers(nums []int) int {
	ans := 0
	for _, num := range nums {
		d := math.Log10(float64(num))
		ans += int(d) % 2
	}

	return ans
}