Arrays - DSA Interview Questions

Arrays are one of the most essential data structures in programming, widely used in problem-solving and interviews. They provide efficient ways to store, access, and manipulate data. These exercises will help you build a strong foundation in array-based problem-solving, covering a range of topics from basics to advanced techniques.

Practice Arrays DSA Coding Problems with Solutions

Learning Objectives:

Gain a clear understanding of array operations, including searching, sorting, and subarray techniques. Apply efficient problem-solving approaches to tackle common array-based coding challenges.

Exercise Instructions:

Start with the first problem and attempt to solve it before checking the hint or solution.
Ensure you understand the logic behind each solution, as this will help you with more complex problems.
Use these exercises to reinforce your learning and identify areas that may require further study.

1. Find the largest element in an array

Required Input:

arr = [3, 1, 7, 4, 9, 2]

Expected Output:

Code In Python

def find_largest_element(arr): # write your logic here pass # prefilled input arr = [3, 1, 7, 4, 9, 2] print(find_largest_element(arr))

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2. Find the second largest element in an array

Required Input:

arr = [10, 5, 8, 12, 3]

Expected Output:

Code In Python

def find_second_largest(arr): # write your logic here pass # prefilled input arr = [10, 5, 8, 12, 3] print(find_second_largest(arr))

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3. Check if an array is sorted

Required Input:

arr = [1, 2, 3, 4, 5]

Expected Output:

True

Code In Python

def is_sorted(arr): # write your logic here pass # prefilled input arr = [1, 2, 3, 4, 5] print(is_sorted(arr))

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4. Remove duplicates from a sorted array

Required Input:

arr = [1, 1, 2, 2, 3, 4, 4, 5]

Expected Output:

[1, 2, 3, 4, 5]

Code In Python

def remove_duplicates(arr): # write your logic here pass # prefilled input arr = [1, 1, 2, 2, 3, 4, 4, 5] print(remove_duplicates(arr))

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5. Move zeros to the end

Required Input:

arr = [0, 1, 0, 3, 12]

Expected Output:

[1, 3, 12, 0, 0]

Code In Python

def move_zeros(arr): # write your logic here pass # prefilled input arr = [0, 1, 0, 3, 12] print(move_zeros(arr))

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6. Find the missing number in an array

Required Input:

arr = [1, 2, 4, 5, 6]

Expected Output:

Code In Python

def find_missing_number(arr): # write your logic here pass # prefilled input arr = [1, 2, 4, 5, 6] print(find_missing_number(arr))

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7. Find the intersection of two sorted arrays

Required Input:

arr1 = [1, 2, 3, 4, 5], arr2 = [3, 4, 5, 6, 7]

Expected Output:

[3, 4, 5]

Code In Python

def find_intersection(arr1, arr2): # write your logic here pass # prefilled input arr1 = [1, 2, 3, 4, 5] arr2 = [3, 4, 5, 6, 7] print(find_intersection(arr1, arr2))

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8. Left rotate an array by one position

Required Input:

arr = [10, 20, 30, 40, 50]

Expected Output:

[20, 30, 40, 50, 10]

Code In Python

def left_rotate_one(arr): # write your logic here pass # prefilled input arr = [10, 20, 30, 40, 50] print(left_rotate_one(arr))

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9. Kadane’s algorithm (maximum subarray sum)

Required Input:

arr = [-2, 1, -3, 4, -1, 2, 1, -5, 4]

Expected Output:

Code In Python

def max_subarray_sum(arr): # write your logic here pass # prefilled input arr = [-2, 1, -3, 4, -1, 2, 1, -5, 4] print(max_subarray_sum(arr))

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10. Find the majority element

Required Input:

arr = [3, 3, 4, 2, 3, 3, 3]

Expected Output:

Code In Python

def majority_element(arr): # write your logic here pass # prefilled input arr = [3, 3, 4, 2, 3, 3, 3] print(majority_element(arr))

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