240. Search a 2D Matrix II刷题笔记

如果采用二向搜索可能会更快点。从左下角直接开始搜索，比较简单，加上剪枝判断后速度也还可以

class Solution:
    def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:
        m = len(matrix)-1
        n = len(matrix[0])-1
        if target < matrix[0][0] or target > matrix[m][n]:
            return False
        i = m
        j = 0
        while i>= 0 and j<=n:
            if matrix[i][j]>target:
                i -= 1
            elif matrix[i][j]<target:
                j += 1
            else:
                return True
        return False