What is the key pattern to solve the 'Check if Grid Satisfies Conditions' problem?

The key pattern involves checking if all elements in each row and column of the grid are identical, either row-wise or column-wise.

What approach should be used to check if grid elements satisfy the conditions?

You should iterate through each row and column to check if all elements within each are identical and then return the result based on this verification.

Can this problem be solved in less than O(m * n) time?

No, since we need to check every element in the grid to ensure it satisfies the conditions, a solution with O(m * n) time complexity is optimal.

How can I check if the elements in a grid are the same across rows and columns?

You can check if all elements in each row are the same first, then do the same for columns by comparing the elements in the same column across all rows.

What are the constraints for solving the 'Check if Grid Satisfies Conditions' problem?

The grid must have dimensions between 1 and 10 for both rows and columns, and the values of the elements are between 0 and 9.

#3142

Easy

auto_awesome数组·matrix

LeetCode 题解工作台

判断矩阵是否满足条件

给你一个大小为 m x n 的二维矩阵 grid 。你需要判断每一个格子 grid[i][j] 是否满足：如果它下面的格子存在，那么它需要等于它下面的格子，也就是 grid[i][j] == grid[i + 1][j] 。如果它右边的格子存在，那么它需要不等于它右边的格子，也就是 grid[i…

数组矩阵

题目描述

给你一个大小为 m x n 的二维矩阵 grid 。你需要判断每一个格子 grid[i][j] 是否满足：

如果它下面的格子存在，那么它需要等于它下面的格子，也就是 grid[i][j] == grid[i + 1][j] 。
如果它右边的格子存在，那么它需要不等于它右边的格子，也就是 grid[i][j] != grid[i][j + 1] 。

如果所有格子都满足以上条件，那么返回 true ，否则返回 false 。

示例 1：

输入：grid = [[1,0,2],[1,0,2]]

输出：true

解释：

网格图中所有格子都符合条件。

示例 2：

输入：grid = [[1,1,1],[0,0,0]]

输出：false

解释：

同一行中的格子值都相等。

示例 3：

输入：grid = [[1],[2],[3]]

输出：false

解释：

同一列中的格子值不相等。

提示：

1 <= n, m <= 10
0 <= grid[i][j] <= 9

lightbulb

解题思路

方法一：模拟

我们可以遍历每一个格子，判断其是否满足题目条件，如果有一个格子不满足条件，我们就返回 false，否则返回 true。

时间复杂度 $O(m \times n)$ ，其中 $m$ 和 $n$ 分别是矩阵 grid 的行数和列数。空间复杂度 $O(1)$ 。

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class Solution:
    def satisfiesConditions(self, grid: List[List[int]]) -> bool:
        m, n = len(grid), len(grid[0])
        for i, row in enumerate(grid):
            for j, x in enumerate(row):
                if i + 1 < m and x != grid[i + 1][j]:
                    return False
                if j + 1 < n and x == grid[i][j + 1]:
                    return False
        return True

speed

复杂度分析

指标	值
时间	Depends on the final approach
空间	Depends on the final approach

psychology

面试官常问的追问

外企场景

question_mark
Look for an approach that involves iterating through rows and columns to check for uniformity.
question_mark
Ensure the candidate efficiently handles the grid with a simple comparison for correctness.
question_mark
Test whether the candidate identifies the pattern of checking rows and columns in grid validation.

warning

常见陷阱

外企场景

error
Not correctly iterating through each row or column to check for uniformity.
error
Misunderstanding the constraints and mistakenly returning incorrect results for non-uniform cells.
error
Overcomplicating the solution by introducing unnecessary operations or data structures.

swap_horiz

进阶变体

外企场景

arrow_right_alt
Consider cases where grid elements may be different but still satisfy conditions.
arrow_right_alt
Try solving the problem by verifying one condition first and then moving to the next step for optimization.
arrow_right_alt
Explore optimization for larger grids when applicable by considering reduced time complexity solutions.

help

常见问题

外企场景

继续练习

#3148 矩阵中的最大得分 #3127 构造相同颜色的正方形 #3122 使矩阵满足条件的最少操作次数