Add solution #1053

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,122 LeetCode solutions in JavaScript
+# 1,123 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -858,6 +858,7 @@
 1049|[Last Stone Weight II](./solutions/1049-last-stone-weight-ii.js)|Medium|
 1051|[Height Checker](./solutions/1051-height-checker.js)|Easy|
 1052|[Grumpy Bookstore Owner](./solutions/1052-grumpy-bookstore-owner.js)|Medium|
+1053|[Previous Permutation With One Swap](./solutions/1053-previous-permutation-with-one-swap.js)|Medium|
 1071|[Greatest Common Divisor of Strings](./solutions/1071-greatest-common-divisor-of-strings.js)|Easy|
 1072|[Flip Columns For Maximum Number of Equal Rows](./solutions/1072-flip-columns-for-maximum-number-of-equal-rows.js)|Medium|
 1073|[Adding Two Negabinary Numbers](./solutions/1073-adding-two-negabinary-numbers.js)|Medium|

solutions/1053-previous-permutation-with-one-swap.js

@@ -0,0 +1,40 @@
+/**
+ * 1053. Previous Permutation With One Swap
+ * https://leetcode.com/problems/previous-permutation-with-one-swap/
+ * Difficulty: Medium
+ *
+ * Given an array of positive integers arr (not necessarily distinct), return the lexicographically
+ * largest permutation that is smaller than arr, that can be made with exactly one swap. If it
+ * cannot be done, then return the same array.
+ *
+ * Note that a swap exchanges the positions of two numbers arr[i] and arr[j]
+ */
+
+/**
+ * @param {number[]} arr
+ * @return {number[]}
+ */
+var prevPermOpt1 = function(arr) {
+  const result = [...arr];
+  let swapIndex = -1;
+
+  for (let i = arr.length - 2; i >= 0; i--) {
+    if (arr[i] > arr[i + 1]) {
+      swapIndex = i;
+      break;
+    }
+  }
+
+  if (swapIndex === -1) return arr;
+
+  let maxLessIndex = swapIndex + 1;
+  for (let j = swapIndex + 2; j < arr.length; j++) {
+    if (arr[j] < arr[swapIndex] && arr[j] > arr[maxLessIndex]) {
+      maxLessIndex = j;
+    }
+  }
+
+  [result[swapIndex], result[maxLessIndex]] = [result[maxLessIndex], result[swapIndex]];
+
+  return result;
+};