Smallest Index With Equal Value

Problem Description

Given a 0-indexed integer array nums, return the smallest index i of nums such that i mod 10 == nums[i], or -1 if such index does not exist.

Key Insights

• The problem requires checking each index i in the array to see if the condition i mod 10 == nums[i] holds.
• Since the array has a maximum length of 100, a simple linear scan through the array is sufficient.
• The values in the array range from 0 to 9, which means we only need to check the last digit of the index.

Space and Time Complexity

Time Complexity: O(n) where n is the length of the array nums.
Space Complexity: O(1) as we use a constant amount of space.

Solution

To solve this problem, we will iterate through the array nums using a loop. For each index i, we will calculate i mod 10 and compare it with nums[i]. If they are equal, we return the index. If no such index is found after checking all elements, we return -1. This approach uses a simple array traversal and requires no additional data structures.

Code Solutions