Add solution #3446

Author: JoshCrozier

README.md

@@ -2739,6 +2739,7 @@
 3442|[Maximum Difference Between Even and Odd Frequency I](./solutions/3442-maximum-difference-between-even-and-odd-frequency-i.js)|Easy|
 3443|[Maximum Manhattan Distance After K Changes](./solutions/3443-maximum-manhattan-distance-after-k-changes.js)|Medium|
 3445|[Maximum Difference Between Even and Odd Frequency II](./solutions/3445-maximum-difference-between-even-and-odd-frequency-ii.js)|Hard|
+3446|[Sort Matrix by Diagonals](./solutions/3446-sort-matrix-by-diagonals.js)|Medium|
 3450|[Maximum Students on a Single Bench](./solutions/3450-maximum-students-on-a-single-bench.js)|Easy|
 3452|[Sum of Good Numbers](./solutions/3452-sum-of-good-numbers.js)|Easy|
 3460|[Longest Common Prefix After at Most One Removal](./solutions/3460-longest-common-prefix-after-at-most-one-removal.js)|Medium|

solutions/3446-sort-matrix-by-diagonals.js

@@ -0,0 +1,40 @@
+/**
+ * 3446. Sort Matrix by Diagonals
+ * https://leetcode.com/problems/sort-matrix-by-diagonals/
+ * Difficulty: Medium
+ *
+ * You are given an n x n square matrix of integers grid. Return the matrix such that:
+ * - The diagonals in the bottom-left triangle (including the middle diagonal) are sorted
+ *   in non-increasing order.
+ * - The diagonals in the top-right triangle are sorted in non-decreasing order.
+ */
+
+/**
+ * @param {number[][]} grid
+ * @return {number[][]}
+ */
+var sortMatrix = function(grid) {
+  const n = grid.length;
+  const map = new Map();
+
+  for (let i = 0; i < n; i++) {
+    for (let j = 0; j < n; j++) {
+      const key = i - j;
+      if (!map.has(key)) {
+        map.set(key, key < 0
+          ? new PriorityQueue((a, b) => a - b)
+          : new PriorityQueue((a, b) => b - a));
+      }
+      map.get(key).enqueue(grid[i][j]);
+    }
+  }
+
+  for (let i = 0; i < n; i++) {
+    for (let j = 0; j < n; j++) {
+      const key = i - j;
+      grid[i][j] = map.get(key).dequeue();
+    }
+  }
+
+  return grid;
+};