ref:https://blog.csdn.net/u010089444/article/details/70854510

所以（python）：

python
class Solution:
    def findNumberIn2DArray(self, matrix: List[List[int]], target: int) -> bool:
        def find(x,y):
            if not (x<len(matrix) and y ):
                return False
            elif matrix[x][y-1]==target:
                return True
            elif matrix[x][y-1]>target:
                return find(x,y-1) # 目标值小，往左子树找
            else:
                return find(x+1,y) # 目标值大，往右子树找
        if len(matrix):
            return find(0,len(matrix[0]))
        else:
            return False