Search a 2D Matrix II - Python Leetcode

 Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:

• Integers in each row are sorted in ascending from left to right.
• Integers in each column are sorted in ascending from top to bottom.

Example:

Consider the following 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]
]

Using Search Space Reduction Method

Given target = 5, return true.

Given target = 20, return false.

class Solution:

    def searchMatrix(self, matrix, target):

        """

        :type matrix: List[List[int]]

        :type target: int

        :rtype: bool

        """

        if not matrix:

            return False

        rows = len(matrix)

        cols = len(matrix[0])

        

        if rows == 0 or cols ==0:

            return False

        

        row = rows-1

        col = 0

        

        while row >=0 and col < cols:

            if target == matrix[row][col]:

                return True

            elif target < matrix[row][col]:

                row -= 1

            else:

                col+=1

        return False

        Time Complexity : O(m+n)

        Space Complexity : O(1)