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Write Java code for this question: You are given the heads of two sorted linked ...

Mar 13, 2024

Write Java code for this question: You are given the heads of two sorted linked lists list1 and list2. Merge the two lists into one sorted list. The list should be made by splicing together the nodes of the first two lists. Return the head of the merged linked list.

java

Explanation

The provided Java code defines a ListNode class for the linked list nodes and a Solution class with a method to merge two sorted linked lists into one sorted list. The main function tests the mergeTwoLists method with two use cases and prints the merged lists to verify the results.

Step-by-step Instruction

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Implement the mergeTwoLists method in the Solution class to merge two sorted linked lists

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Use a dummy node to simplify the merging process and maintain a current pointer to build the new list

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Use a while loop to iterate through both lists, choosing the smaller head node to attach to the merged list

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After the loop, attach any remaining nodes from either list to the merged list

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Return the head of the merged list, which is the next node of the dummy node

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Define the main method to test the mergeTwoLists method with specific use cases

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Print the merged list to verify the correctness of the mergeTwoLists method

Time Complexity

The time complexity is O(n + m), where n and m are the lengths of the two lists, because each element from both lists is visited at most once.

Space Complexity

The space complexity is O(1), as we only use a fixed number of extra pointers, regardless of the input list sizes.