Practice Two Pointers Questions for DSA Coding Interviews

11. Check if a String is a Palindrome

Required Input:

s = "madam"

Expected Output:

True

Code In Python

def is_palindrome_string(s): # Write your logic here pass # Prefilled input s = "madam" print(is_palindrome_string(s))

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12. Find the Middle of a Sorted Rotated Array

Required Input:

arr = [4, 5, 6, 7, 0, 1, 2]

Expected Output:

Code In Python

def find_middle_rotated(arr): # Write your logic here pass # Prefilled input arr = [4, 5, 6, 7, 0, 1, 2] print(find_middle_rotated(arr))

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13. Find Triplets That Sum to Zero

Required Input:

arr = [-1, 0, 1, 2, -1, -4]

Expected Output:

[[-1, -1, 2], [-1, 0, 1]]

Code In Python

def three_sum(arr): # Write your logic here pass # Prefilled input arr = [-1, 0, 1, 2, -1, -4] print(three_sum(arr))

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14. Find the Smallest Subarray with a Sum Greater Than a Given Value

Required Input:

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

Expected Output:

Code In Python

def min_subarray_sum(arr, target): # Write your logic here pass # Prefilled input arr = [2, 3, 1, 2, 4, 3] target = 7 print(min_subarray_sum(arr, target))

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15. Sort an Array with Only 0s, 1s, and 2s (Dutch National Flag Algorithm)

Required Input:

arr = [2, 0, 2, 1, 1, 0]

Expected Output:

[0, 0, 1, 1, 2, 2]

Code In Python

def sort_colors(arr): # Write your logic here pass # Prefilled input arr = [2, 0, 2, 1, 1, 0] print(sort_colors(arr))

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16. Find the Maximum Sum of a Subarray of Size K

Required Input:

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

Expected Output:

Code In Python

def max_sum_subarray_k(arr, k): # Write your logic here pass # Prefilled input arr = [2, 1, 5, 1, 3, 2] k = 3 print(max_sum_subarray_k(arr, k))

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17. Find the Longest Substring Without Repeating Characters

Required Input:

s = "abcabcbb"

Expected Output:

Code In Python

def longest_unique_substring(s): # Write your logic here pass # Prefilled input s = "abcabcbb" print(longest_unique_substring(s))

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18. Find Pairs with a Given Difference

Required Input:

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

Expected Output:

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

Code In Python

def find_pairs_with_difference(arr, k): # Write your logic here pass # Prefilled input arr = [1, 5, 3, 4, 2] k = 2 print(find_pairs_with_difference(arr, k))

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19. Find the Median of Two Sorted Arrays

Required Input:

arr1 = [1, 3], arr2 = [2]

Expected Output:

Code In Python

def find_median_sorted_arrays(arr1, arr2): # Write your logic here pass # Prefilled input arr1 = [1, 3] arr2 = [2] print(find_median_sorted_arrays(arr1, arr2))

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20. Find the Minimum Difference Pair in Two Arrays

Required Input:

arr1 = [1, 4, 7, 10], arr2 = [2, 5, 8, 12]

Expected Output:

[1, 2]

Code In Python

def min_difference_pair(arr1, arr2): # Write your logic here pass # Prefilled input arr1 = [1, 4, 7, 10] arr2 = [2, 5, 8, 12] print(min_difference_pair(arr1, arr2))

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