Add solution #1001

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,079 LeetCode solutions in JavaScript
+# 1,080 LeetCode solutions in JavaScript
 
 [https://leetcode.com/](https://leetcode.com/)
 
@@ -809,6 +809,7 @@
 998|[Maximum Binary Tree II](./solutions/0998-maximum-binary-tree-ii.js)|Medium|
 999|[Available Captures for Rook](./solutions/0999-available-captures-for-rook.js)|Easy|
 1000|[Minimum Cost to Merge Stones](./solutions/1000-minimum-cost-to-merge-stones.js)|Hard|
+1001|[Grid Illumination](./solutions/1001-grid-illumination.js)|Hard|
 1002|[Find Common Characters](./solutions/1002-find-common-characters.js)|Easy|
 1004|[Max Consecutive Ones III](./solutions/1004-max-consecutive-ones-iii.js)|Medium|
 1005|[Maximize Sum Of Array After K Negations](./solutions/1005-maximize-sum-of-array-after-k-negations.js)|Easy|

solutions/1001-grid-illumination.js

@@ -0,0 +1,72 @@
+/**
+ * 1001. Grid Illumination
+ * https://leetcode.com/problems/grid-illumination/
+ * Difficulty: 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.
+ */
+
+/**
+ * @param {number} n
+ * @param {number[][]} lamps
+ * @param {number[][]} queries
+ * @return {number[]}
+ */
+var gridIllumination = function(n, lamps, queries) {
+  const rowCount = new Map();
+  const colCount = new Map();
+  const diag1Count = new Map();
+  const diag2Count = new Map();
+  const lampSet = new Set();
+
+  for (const [r, c] of lamps) {
+    if (!lampSet.has(`${r},${c}`)) {
+      lampSet.add(`${r},${c}`);
+      rowCount.set(r, (rowCount.get(r) || 0) + 1);
+      colCount.set(c, (colCount.get(c) || 0) + 1);
+      diag1Count.set(r - c, (diag1Count.get(r - c) || 0) + 1);
+      diag2Count.set(r + c, (diag2Count.get(r + c) || 0) + 1);
+    }
+  }
+
+  const directions = [[0, 0], [0, 1], [0, -1], [1, 0], [1, 1], [1, -1], [-1, 0], [-1, 1], [-1, -1]];
+  const result = new Array(queries.length);
+
+  for (let i = 0; i < queries.length; i++) {
+    const [r, c] = queries[i];
+    result[i] = (rowCount.get(r) > 0 || colCount.get(c) > 0
+      || diag1Count.get(r - c) > 0 || diag2Count.get(r + c) > 0) ? 1 : 0;
+
+    for (const [dr, dc] of directions) {
+      const newR = r + dr;
+      const newC = c + dc;
+      const key = `${newR},${newC}`;
+
+      if (newR >= 0 && newR < n && newC >= 0 && newC < n && lampSet.has(key)) {
+        lampSet.delete(key);
+        rowCount.set(newR, rowCount.get(newR) - 1);
+        colCount.set(newC, colCount.get(newC) - 1);
+        diag1Count.set(newR - newC, diag1Count.get(newR - newC) - 1);
+        diag2Count.set(newR + newC, diag2Count.get(newR + newC) - 1);
+      }
+    }
+  }
+
+  return result;
+};