240.py

'''
	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.
	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]
	]
	Example 1:

	Input: matrix, target = 5
	Output: true
'''

class Solution(object):
    def searchMatrix(self, matrix, target):
        """
        :type matrix: List[List[int]]
        :type target: int
        :rtype: bool
        """
        
        if not matrix:
        	return False

        left, right = 0, len(matrix[0])-1
        while left < len(matrix) and right >= 0:
        	if matrix[left][right] == target:
        		return True
        	elif matrix[left][right] < target:
        		left += 1
        	else:
        		right -= 1
        return False