How to reverse a stack using Recursion? In this tutorial, I am going to discuss this interesting problem.
Given a stack of integers, we have to write a code to reverse them using recursion. For solving this problem, we don’t have to use any loop constructs (For, While etc.) or any additional data structure.
You can use stack methods like push, pop, isEmpty to solve this problem.
In this tutorial, I am going to discuss a programming question how to segregate even and odd nodes in a linked list or odd even linked list.
Given a singly linked list, We have to write a code to group all odd nodes together followed by the even nodes. We have to group based on node number not the value present in the node.
Try to solve this problem in O(n) time complexity and O(1) space complexity where n is the no. of nodes in a linked list.
Also, the relative order inside both the even and odd groups should remain as it was in the input. The first node is considered odd, the second node even and so on …
For example –
In the this example, Given input linked list is
1 -> 2 -> 3 -> 4 -> NULL
When we segregate even and odd nodes in a Linked List then the output is
1 -> 3 -> 2 -> 4 -> NULL
In this tutorial, I am going to discuss a problem Is Subsequence (check if a string is subsequence of another string).
Given two strings str1 and str2, check if str1 is a subsequence of str2. Both strings consists only of lowercase characters.
Example 1:
Input: str1 = “abc”, str2 = “ahbgdc”
Output: true
Example 2:
Input: s = “axc”, t = “ahbgdc”
Output: false