1295. Find Numbers with Even Number of Digits

Method 1

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.

Method 1

【O(n) time | O(1) space】

package Leetcode.Array;

/**
 * @author zhengxingxing
 * @date 2025/04/30
 */
public class FindNumbersWithEvenNumberOfDigits {

    public static int findNumbers(int[] nums) {
        // Counter to keep track of numbers with even digits
        int count = 0;

        // Iterate through each number in array
        for(int num : nums) {
            // Convert number to string and check if length is even
            // If even, increment counter
            if(String.valueOf(num).length() % 2 == 0) {
                count++;
            }
        }
        return count;
    }

    public static void main(String[] args) {
        // Test Case 1 demonstration
        int[] nums1 = {12,345,2,6,7896};
        System.out.println("Test Case 1 Result: " + findNumbers(nums1)); // Expected output: 2

        // Test Case 2 demonstration
        int[] nums2 = {555,901,482,1771};
        System.out.println("Test Case 2 Result: " + findNumbers(nums2)); // Expected output: 1
    }
}

Method 1

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