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BASA DSA

Add Two Numbers

MediumLinked List

Two nonnegative integers are represented by reversed decimal digits in linked lists. Return their sum in the same representation, with one zero digit for zero.

Example 1

Argument 1: next pointers; tail points to null.Argument 1: next pointers; tail points to null. Vertices: node 0: 8, node 1: 9. Edges: node 0 (8) → node 1 (9).89
Argument 1: next pointers; tail points to null.

Argument 2: next pointers; tail points to null.Argument 2: next pointers; tail points to null. Vertices: node 0: 7. Edges: none.7
Argument 2: next pointers; tail points to null.

Input
l1 = [8,9]
l2 = [7]
Output
[5,0,1]

Explanation

The digits encode 98 and 7; sum 105 is encoded [5,0,1].

Example 2

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

Argument 2: next pointers; tail points to null.Argument 2: next pointers; tail points to null. Vertices: node 0: 0. Edges: none.0
Argument 2: next pointers; tail points to null.

Input
l1 = [0]
l2 = [0]
Output
[0]

Explanation

Zero plus zero returns one zero digit, not an empty list.

Example 3

Argument 1: next pointers; tail points to null.Argument 1: next pointers; tail points to null. Vertices: node 0: 9, node 1: 9. Edges: node 0 (9) → node 1 (9).99
Argument 1: next pointers; tail points to null.

Argument 2: next pointers; tail points to null.Argument 2: next pointers; tail points to null. Vertices: node 0: 1. Edges: none.1
Argument 2: next pointers; tail points to null.

Input
l1 = [9,9]
l2 = [1]
Output
[0,0,1]

Explanation

99+1=100; a carry propagates through both nines and creates a third digit.

Constraints

  • 1 <= length of each list <= 100
  • Digits are 0..9
  • There are no leading zero digits in the represented numbers except zero itself

Function contractaddTwoNumbersArguments: list, list
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