Add solution #1329

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,233 LeetCode solutions in JavaScript
+# 1,234 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1007,6 +1007,7 @@
 1325|[Delete Leaves With a Given Value](./solutions/1325-delete-leaves-with-a-given-value.js)|Medium|
 1326|[Minimum Number of Taps to Open to Water a Garden](./solutions/1326-minimum-number-of-taps-to-open-to-water-a-garden.js)|Hard|
 1328|[Break a Palindrome](./solutions/1328-break-a-palindrome.js)|Medium|
+1329|[Sort the Matrix Diagonally](./solutions/1329-sort-the-matrix-diagonally.js)|Medium|
 1331|[Rank Transform of an Array](./solutions/1331-rank-transform-of-an-array.js)|Easy|
 1332|[Remove Palindromic Subsequences](./solutions/1332-remove-palindromic-subsequences.js)|Easy|
 1333|[Filter Restaurants by Vegan-Friendly, Price and Distance](./solutions/1333-filter-restaurants-by-vegan-friendly-price-and-distance.js)|Medium|

solutions/1329-sort-the-matrix-diagonally.js

@@ -0,0 +1,44 @@
+/**
+ * 1329. Sort the Matrix Diagonally
+ * https://leetcode.com/problems/sort-the-matrix-diagonally/
+ * Difficulty: Medium
+ *
+ * A matrix diagonal is a diagonal line of cells starting from some cell in either the topmost
+ * row or leftmost column and going in the bottom-right direction until reaching the matrix's
+ * end. For example, the matrix diagonal starting from mat[2][0], where mat is a 6 x 3 matrix,
+ * includes cells mat[2][0], mat[3][1], and mat[4][2].
+ *
+ * Given an m x n matrix mat of integers, sort each matrix diagonal in ascending order and return
+ * the resulting matrix.
+ */
+
+/**
+ * @param {number[][]} mat
+ * @return {number[][]}
+ */
+var diagonalSort = function(mat) {
+  const rows = mat.length;
+  const cols = mat[0].length;
+  const diagonals = new Map();
+
+  for (let i = 0; i < rows; i++) {
+    for (let j = 0; j < cols; j++) {
+      const diagonalKey = i - j;
+      if (!diagonals.has(diagonalKey)) {
+        diagonals.set(diagonalKey, []);
+      }
+      diagonals.get(diagonalKey).push(mat[i][j]);
+    }
+  }
+
+  diagonals.forEach(values => values.sort((a, b) => a - b));
+
+  for (let i = 0; i < rows; i++) {
+    for (let j = 0; j < cols; j++) {
+      const diagonalKey = i - j;
+      mat[i][j] = diagonals.get(diagonalKey).shift();
+    }
+  }
+
+  return mat;
+};