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BASA DSA

Reverse Nodes In K Group

HardLinked List

Reverse each complete consecutive group of k nodes in a linked list. Leave a final group shorter than k untouched. Return the new head and change links rather than node values.

Example 1

Argument 1: next pointers; tail points to null.Argument 1: next pointers; tail points to null. Vertices: node 0: 1, node 1: 2, node 2: 3, node 3: 4, node 4: 5. Edges: node 0 (1) → node 1 (2); node 1 (2) → node 2 (3); node 2 (3) → node 3 (4); node 3 (4) → node 4 (5).12345
Argument 1: next pointers; tail points to null.

Input
head = [1,2,3,4,5]
k = 3
Output
[3,2,1,4,5]

Explanation

Reverse complete group 1,2,3; the short remainder 4,5 stays ordered.

Example 2

Argument 1: next pointers; tail points to null.Argument 1: next pointers; tail points to null. Vertices: node 0: 1, node 1: 2, node 2: 3, node 3: 4. Edges: node 0 (1) → node 1 (2); node 1 (2) → node 2 (3); node 2 (3) → node 3 (4).1234
Argument 1: next pointers; tail points to null.

Input
head = [1,2,3,4]
k = 2
Output
[2,1,4,3]

Explanation

Reverse both length-two groups independently into 2,1 and 4,3.

Example 3

Argument 1: next pointers; tail points to null.Argument 1: next pointers; tail points to null. Vertices: node 0: 7. Edges: none.7
Argument 1: next pointers; tail points to null.

Input
head = [7]
k = 1
Output
[7]

Explanation

Groups of one leave order unchanged.

Constraints

  • 1 <= k <= number of nodes <= 5000

Function contractreverseKGroupArguments: list, json
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