How hard is LeetCode 1034. Coloring A Border?

LeetCode 1034. Coloring A Border is rated Medium on LeetCode.

What is the time complexity of LeetCode 1034. Coloring A Border?

The Python solution on this page runs in O(V+E).

What is the space complexity of LeetCode 1034. Coloring A Border?

The Python solution on this page uses O(V) auxiliary space.

What topics does LeetCode 1034. Coloring A Border cover?

LeetCode 1034. Coloring A Border is tagged Depth-First Search, Breadth-First Search, Array and Matrix on LeetCode.

Coloring A Border — LeetCode 1034 Python Solution

MediumDepth-First SearchBreadth-First SearchArrayMatrix

Problem: #1034
Pattern: Matrix and Grid
Reading time: 4 min
Source: leetcode.com

The problem

You are given an m x n integer matrix grid, and three integers row, col, and color. Each value in the grid represents the color of the grid square at that location.

Example

Input: grid = [[1,1],[1,2]], row = 0, col = 0, color = 3
Output: [[3,3],[3,2]]

Python solution

Python

class Solution:
    def colorBorder(
        self, grid: List[List[int]], row: int, col: int, color: int
    ) -> List[List[int]]:
        def dfs(i: int, j: int, c: int) -> None:
            vis[i][j] = True
            for a, b in pairwise((-1, 0, 1, 0, -1)):
                x, y = i + a, j + b
                if 0 <= x < m and 0 <= y < n:
                    if not vis[x][y]:
                        if grid[x][y] == c:
                            dfs(x, y, c)
                        else:
                            grid[i][j] = color
                else:
                    grid[i][j] = color

        m, n = len(grid), len(grid[0])
        vis = [[False] * n for _ in range(m)]
        dfs(row, col, grid[row][col])
        return grid

Complexity

Measure	Complexity
Time	O(V+E)
Space	O(V) auxiliary

Pattern: Matrix and Grid

Treat a 2-D grid as a graph whose neighbours are the four adjacent cells. LeetCode 1034. Coloring A Border is filed here because LeetCode tags it Matrix, which is the vocabulary this hub collects.

The matrix and grid guide has the Python template for the pattern and the 216 LeetCode problems that use it.

Frequently asked questions

How hard is LeetCode 1034. Coloring A Border?: LeetCode 1034. Coloring A Border is rated Medium on LeetCode.
What is the time complexity of LeetCode 1034. Coloring A Border?: The Python solution on this page runs in O(V+E).
What is the space complexity of LeetCode 1034. Coloring A Border?: The Python solution on this page uses O(V) auxiliary space.
What topics does LeetCode 1034. Coloring A Border cover?: LeetCode 1034. Coloring A Border is tagged Depth-First Search, Breadth-First Search, Array and Matrix on LeetCode.