74. Search a 2D Matrix

class Solution:
    def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:
        # time O(Nlg(N)) N = cols*rows  space O(1)
        """
        main idea:  convert 2D to 1D ,and mirrow 1D value to 2D by // col and % col for row_pos and col_pos.
        """
        # edge case: 
        if not matrix or not matrix[0] or target < matrix[0][0] or target > matrix[-1][-1] :
            return False
        row = len(matrix)
        col = len(matrix[0])
        l,r = 0,row*col-1
        while l <= r:
            mid = l + (r-l)//2
            i = mid//col
            j = mid%col
            if matrix[i][j]< target:
                l = mid+1
            elif matrix[i][j]> target:
                r = mid-1
            else:
                return True