search-a-2d-matrix-ii

[shashantsah]

Description

We need to efficiently search for a target value in a matrix where rows and columns are sorted in ascending order. The matrix is structured such that lower values are towards the top-left corner and higher values are towards the bottom-right corner.

Approach

The provided solution utilizes a two-pointer approach starting from the bottom-left corner of the matrix:

Begin from the bottom-left corner (matrix[n-1][0]).

• If the current value is equal to the target, return true.

• If the current value is greater than the target, move upwards to the next row (row--).

• If the current value is less than the target, move to the right to the next column (col++).

• This approach efficiently narrows down the search space by leveraging the sorted properties of both rows and columns.

Put check marks:

• Have you made changes in README file?
• Added problem & solution under correct topic.
• Specified Space & Time complexity.
• Specified difficulty level, tag & Note(if any).

How Has This Been Tested?

• Implemented test cases for matrix search.

  • Test Case 1:

    • Input Matrix:

      [[1,4,7,11,15],
       [2,5,8,12,19],
       [3,6,9,16,22],
       [10,13,14,17,24],
       [18,21,23,26,30]]
      

    • Target: 5
    • Expected Output: True
    • Actual Output: True (verified)

  • Test Case 2:

    • Input Matrix:

      [[1,4,7,11,15],
       [2,5,8,12,19],
       [3,6,9,16,22],
       [10,13,14,17,24],
       [18,21,23,26,30]]
      

    • Target: 20
    • Expected Output: False
    • Actual Output: False (verified)

Make sure all below guidelines are followed else PR will get Reject:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code so that it is easy to understand
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

[welcome]

I can tell this is your first pull request! Thank you I'm so honored. 🎉🎉🎉 I'll take a look at it ASAP!