Is Find Numbers with Even Number of Digits easy or hard?

LeetCode classifies this problem as Easy. The logic involves simple array traversal and digit counting. It is commonly used as a beginner exercise to practice iteration and basic math operations.

Find Numbers with Even Number of Digits Python/Java solution

In Python, iterate through the list and check len(str(num)) % 2 == 0. In Java, convert the number using String.valueOf(num) and check its length. Both implementations run in O(n) time and require only constant extra space.

How to solve Find Numbers with Even Number of Digits in O(n)?

Iterate through the array and compute the digit count for each number. You can convert the number to a string and check its length or compute digits using floor(log10(num)) + 1. Increment a counter whenever the digit count is even. The array is scanned once, giving O(n) time complexity.

What is the best approach for Find Numbers with Even Number of Digits?

The simplest approach converts each integer to a string and checks if the string length is even. This runs in O(n) time because each array element is processed once. An alternative uses the formula floor(log10(num)) + 1 to compute digit length mathematically, also in O(n) time and O(1) space.

Is Find Numbers with Even Number of Digits asked at Google/Amazon/Meta?

Problems like this appear frequently in screening rounds and coding assessments because they test basic array iteration and number manipulation. While the exact question may vary, similar easy problems are commonly used by companies such as Amazon and other large tech firms to evaluate coding fundamentals.

What data structure is used in Find Numbers with Even Number of Digits?

The primary data structure is an array that stores the integers. The algorithm simply iterates through the array and evaluates each value individually. No additional complex structures like hash maps or trees are required.

What is the time complexity of Find Numbers with Even Number of Digits?

The time complexity is O(n), where n is the number of elements in the array. Each number is inspected exactly once to determine its digit length. Digit counting itself is constant time because integers have a limited number of digits.

Description Hints 2 Solution Video 4:34

1295. Find Numbers with Even Number of Digits

Easy79.7% acceptance7 companies

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] <= 10⁵

Asked at 7 companies

Quora

TCS

Google Meta Bloomberg Amazon Microsoft

Topics

Array Math

Hints open one at a time

Hint 1

How to compute the number of digits of a number ?

Hint 2

Divide the number by 10 again and again to get the number of digits.

4:34

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