Search_a_2D_Marix

class Solution:
    def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:
        m=len(matrix)
        n=len(matrix[0])
        low, high = 0, (m*n)-1
        while low<=high:
            mid = low + (high-low)//2
            r_idx = mid//n
            c_idx = mid%n
            mid_element = matrix[r_idx][c_idx]
            if mid_element == target:
                return True
            elif mid_element<target:
                low = mid+1
            else:
                high = mid-1
        return False