This content originally appeared on DEV Community and was authored by Leetcode
Approach
- Find the node at index a – 1 and b
- Set the next of the node at index
- Find the last node of list2
- Set the next of the last node of list2 to the next of the node at index b
- Return the head of the list
Complexity
Time complexity: O(n)
Space complexity: O(1)
Java Code
class Solution {
public ListNode mergeInBetween(ListNode list1, int a, int b, ListNode list2) {
ListNode start = list1;
ListNode end = list1;
for (int i = 0; i < a - 1; i++) {
start = start.next;
}
for (int i = 0; i < b; i++) {
end = end.next;
}
start.next = list2;
while (list2.next != null) {
list2 = list2.next;
}
list2.next = end.next;
return list1;
}
}
This content originally appeared on DEV Community and was authored by Leetcode