Plus One Solution for Wipro

Company: Wipro · Difficulty: Easy · Topics: Array, Math

Problem Statement

You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order.

Increment the large integer by one and return the resulting array of digits.

Examples

Example 1:

Input: digits = [1,2,3]

Output: [1,2,4]

Explanation: The array represents the integer 123. Incrementing by 1 gives 123 + 1 = 124.

Example 2:

Input: digits = [9,9,9]

Output: [1,0,0,0]

Explanation: The array represents the integer 999. Incrementing by 1 gives 999 + 1 = 1000.

Approach

Right-to-Left Traversal (Optimal)

1. Start from the rightmost digit

2. If the digit is less than 9, increment it and return

3. If the digit is 9, set it to 0 and continue to the left

4. If all digits are 9, add a new digit 1 at the beginning

Time and Space Complexity

• Time Complexity: O(n) - Single pass through array (worst case)
• Space Complexity: O(1) - In-place modification (except when adding new digit)

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