# LeetCode 1034. Coloring A Border

Given a 2-dimensional `grid`

of integers, each value in the grid represents the color of the grid square at that location.

Two squares belong to the same *connected component* if and only if they have the same color and are next to each other in any of the 4 directions.

The *border* of a connected component is all the squares in the connected component that are either 4-directionally adjacent to a square not in the component, or on the boundary of the grid (the first or last row or column).

Given a square at location `(r0, c0)`

in the grid and a `color`

, color the border of the connected component of that square with the given `color`

, and return the final `grid`

.

**Example 1:**

1 | Input: grid = [[1,1],[1,2]], r0 = 0, c0 = 0, color = 3 |

**Example 2:**

1 | Input: grid = [[1,2,2],[2,3,2]], r0 = 0, c0 = 1, color = 3 |

**Example 3:**

1 | Input: grid = [[1,1,1],[1,1,1],[1,1,1]], r0 = 1, c0 = 1, color = 2 |

**Note:**

`1 <= grid.length <= 50`

`1 <= grid[0].length <= 50`

`1 <= grid[i][j] <= 1000`

`0 <= r0 < grid.length`

`0 <= c0 < grid[0].length`

`1 <= color <= 1000`

BFS搞就完事了。

1 | class Solution { |