Problem title
Difficulty
Avg time to solve

Increasing Subsegment
Moderate
15 mins
Minimum time
Moderate
15 mins
X OR Y
Easy
15 mins
No Adjacent Same
Easy
10 mins
Sum Of Squares Of First N Natural Numbers
Easy
15 mins
Find All Anagrams in a String
Easy
15 mins
Finding Binary In Decimal
Easy
15 mins
Board Cutting
Moderate
10 mins
XOR Property
Easy
15 mins
Counting Pairs
Moderate
35 mins
4

Add First and Second Reversed Half

Difficulty: MEDIUM
Contributed By
Avg. time to solve
42 min
Success Rate
60%

Problem Statement

You have been given a Linked List of 'N' nodes such that each node represents a single digit.

Your task is to return a node 'X', where 'X' represents the head of the Linked List storing the digits of the sum(most significant digit at the head) formed by adding 1st half and reverse of 2nd half of the given linked list.

Note:

1. When 'N' is odd consider the middle element to be part of 1st half.
2. The sum should not contain any leading zero, except the number 0 itself.

For example:

Given a Linked List: 1-2-3-4-5-5-6

First half: 1-2-3-4   
Reversed second half: 6-5-5

Output linkedlist: 1-8-8-9 = (1234 + 655 = 1889)

Follow Up:

Can you add both halves without finding the length of LinkedList and in O(1) space?
Input format :
A single line of input contains the elements of the singly linked list separated by a single space and terminated by -1.
Output format :
For each input, print a single line containing a string denoting the required sum.
Note:
You do not need to print anything; it has already been taken care of. Just implement the given function.
Constraints :
0 <= 'N' <= 10 ^ 5
0 <= 'DATA' <= 9

Where 'N' is the number of nodes in linked list and 'DATA' is the integer value in each node.

Time Limit: 1 sec
Sample Input 1:
1 2 4 5 6 -1
Sample Output 1:
189
Explanation for Sample Input 1:
The first half of the given linkedlist is: 1-2-4
The second half of the given linkedlist is: 6-5
Sum of both parts = 124 + 65 = 189
Sample Input 2:
3 9 0 1 1 0 -1
Sample Output 2:
401
Reset Code
Full screen
copy-code
Console