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Java-based LeetCode algorithm problem solutions, regularly updated
1001\. Grid Illumination
Hard
There is a 2D `grid` of size `n x n` where each cell of this grid has a lamp that is initially **turned off**.
You are given a 2D array of lamp positions `lamps`, where lamps[i] = [rowi, coli]
indicates that the lamp at grid[rowi][coli]
is **turned on**. Even if the same lamp is listed more than once, it is turned on.
When a lamp is turned on, it **illuminates its cell** and **all other cells** in the same **row, column, or diagonal**.
You are also given another 2D array `queries`, where queries[j] = [rowj, colj]
. For the jth
query, determine whether grid[rowj][colj]
is illuminated or not. After answering the jth
query, **turn off** the lamp at grid[rowj][colj]
and its **8 adjacent lamps** if they exist. A lamp is adjacent if its cell shares either a side or corner with grid[rowj][colj]
.
Return _an array of integers_ `ans`_,_ _where_ `ans[j]` _should be_ `1` _if the cell in the_ jth
_query was illuminated, or_ `0` _if the lamp was not._
**Example 1:**
![](https://assets.leetcode.com/uploads/2020/08/19/illu_1.jpg)
**Input:** n = 5, lamps = [[0,0],[4,4]], queries = [[1,1],[1,0]]
**Output:** [1,0]
**Explanation:** We have the initial grid with all lamps turned off. In the above picture we see the grid after turning on the lamp at grid[0][0] then turning on the lamp at grid[4][4]. The 0th query asks if the lamp at grid[1][1] is illuminated or not (the blue square). It is illuminated, so set ans[0] = 1. Then, we turn off all lamps in the red square. ![](https://assets.leetcode.com/uploads/2020/08/19/illu_step1.jpg) The 1st query asks if the lamp at grid[1][0] is illuminated or not (the blue square). It is not illuminated, so set ans[1] = 0. Then, we turn off all lamps in the red rectangle. ![](https://assets.leetcode.com/uploads/2020/08/19/illu_step2.jpg)
**Example 2:**
**Input:** n = 5, lamps = [[0,0],[4,4]], queries = [[1,1],[1,1]]
**Output:** [1,1]
**Example 3:**
**Input:** n = 5, lamps = [[0,0],[0,4]], queries = [[0,4],[0,1],[1,4]]
**Output:** [1,1,0]
**Constraints:**
* 1 <= n <= 109
* `0 <= lamps.length <= 20000`
* `0 <= queries.length <= 20000`
* `lamps[i].length == 2`
* 0 <= rowi, coli < n
* `queries[j].length == 2`
* 0 <= rowj, colj < n