Add solution #1320

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,229 LeetCode solutions in JavaScript
+# 1,230 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1001,6 +1001,7 @@
 1317|[Convert Integer to the Sum of Two No-Zero Integers](./solutions/1317-convert-integer-to-the-sum-of-two-no-zero-integers.js)|Easy|
 1318|[Minimum Flips to Make a OR b Equal to c](./solutions/1318-minimum-flips-to-make-a-or-b-equal-to-c.js)|Medium|
 1319|[Number of Operations to Make Network Connected](./solutions/1319-number-of-operations-to-make-network-connected.js)|Medium|
+1320|[Minimum Distance to Type a Word Using Two Fingers](./solutions/1320-minimum-distance-to-type-a-word-using-two-fingers.js)|Hard|
 1323|[Maximum 69 Number](./solutions/1323-maximum-69-number.js)|Easy|
 1324|[Print Words Vertically](./solutions/1324-print-words-vertically.js)|Medium|
 1331|[Rank Transform of an Array](./solutions/1331-rank-transform-of-an-array.js)|Easy|

solutions/1320-minimum-distance-to-type-a-word-using-two-fingers.js

@@ -0,0 +1,56 @@
+/**
+ * 1320. Minimum Distance to Type a Word Using Two Fingers
+ * https://leetcode.com/problems/minimum-distance-to-type-a-word-using-two-fingers/
+ * Difficulty: Hard
+ *
+ * You have a keyboard layout as shown above in the X-Y plane, where each English uppercase letter
+ * is located at some coordinate.
+ *
+ * For example, the letter 'A' is located at coordinate (0, 0), the letter 'B' is located at
+ * coordinate (0, 1), the letter 'P' is located at coordinate (2, 3) and the letter 'Z' is located
+ * at coordinate (4, 1).
+ *
+ * Given the string word, return the minimum total distance to type such string using only two
+ * fingers.
+ *
+ * The distance between coordinates (x1, y1) and (x2, y2) is |x1 - x2| + |y1 - y2|.
+ *
+ * Note that the initial positions of your two fingers are considered free so do not count towards
+ * your total distance, also your two fingers do not have to start at the first letter or the first
+ * two letters.
+ */
+
+/**
+ * @param {string} word
+ * @return {number}
+ */
+var minimumDistance = function(word) {
+  const memo = {};
+  return dp(0, null, null);
+
+  function dp(index, finger1, finger2) {
+    if (index === word.length) return 0;
+
+    const key = `${index},${finger1},${finger2}`;
+    if (memo[key] !== undefined) return memo[key];
+
+    const nextChar = word[index];
+    const moveFinger1 = distance(finger1, nextChar) + dp(index + 1, nextChar, finger2);
+    const moveFinger2 = distance(finger2, nextChar) + dp(index + 1, finger1, nextChar);
+
+    memo[key] = Math.min(moveFinger1, moveFinger2);
+    return memo[key];
+  }
+
+  function getPosition(char) {
+    const code = char.charCodeAt(0) - 65;
+    return [Math.floor(code / 6), code % 6];
+  }
+
+  function distance(from, to) {
+    if (from === null) return 0;
+    const [x1, y1] = getPosition(from);
+    const [x2, y2] = getPosition(to);
+    return Math.abs(x1 - x2) + Math.abs(y1 - y2);
+  }
+};