Given two linked lists, the task is to check whether the first list is present in 2nd list or not.
Input : list1 = 10->20 list2 = 5->10->20 Output : LIST FOUND Input : list1 = 1->2->3->4 list2 = 1->2->1->2->3->4 Output : LIST FOUND Input : list1 = 1->2->3->4 list2 = 1->2->2->1->2->3 Output : LIST NOT FOUND
1- Take first node of second list.
2- Start matching the first list from this first node.
3- If whole lists match return true.
4- Else break and take first list to the first node again.
5- And take second list to its second node.
6- Repeat these steps until any of linked lists becomes empty.
7- If first list becomes empty then list found else not.
Below is C++ implementation.
Time Complexity : O(m*n) where m is the number of nodes in second list and n in first.
Above code can be optimized by using extra space i.e. stores the list into two strings and apply KMP algorithm. Refer https://ide.geeksforgeeks.org/3fXUaV for implementation provided by Nishant Singh .
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