Add solution #72

Author: JoshCrozier

0072-edit-distance.js

@@ -0,0 +1,38 @@
+/**
+ * 72. Edit Distance
+ * https://leetcode.com/problems/edit-distance/
+ * Difficulty: Medium
+ *
+ * Given two strings word1 and word2, return the minimum number of operations required to
+ * convert word1 to word2.
+ *
+ * You have the following three operations permitted on a word:
+ * - Insert a character
+ * - Delete a character
+ * - Replace a character
+ */
+
+/**
+ * @param {string} word1
+ * @param {string} word2
+ * @return {number}
+ */
+var minDistance = function(word1, word2) {
+  const cache = new Array(word1.length + 1).fill(0).map(() => new Array(word2.length + 1));
+
+  for (let i = 0; i <= word1.length; i++) {
+    for (let j = 0; j <= word2.length; j++) {
+      if (i === 0) {
+        cache[0][j] = j;
+      } else if (j === 0) {
+        cache[i][0] = i;
+      } else if (word1[i - 1] == word2[j - 1]) {
+        cache[i][j] = cache[i - 1][j - 1];
+      } else {
+        cache[i][j] = Math.min(cache[i][j - 1], cache[i - 1][j - 1], cache[i - 1][j]) + 1;
+      }
+    }
+  }
+
+  return cache[word1.length][word2.length];
+};

README.md

@@ -75,6 +75,7 @@
 69|[Sqrt(x)](./0069-sqrtx.js)|Medium|
 70|[Climbing Stairs](./0070-climbing-stairs.js)|Easy|
 71|[Simplify Path](./0071-simplify-path.js)|Medium|
+72|[Edit Distance](./0072-edit-distance.js)|Medium|
 73|[Set Matrix Zeroes](./0073-set-matrix-zeroes.js)|Medium|
 74|[Search a 2D Matrix](./0074-search-a-2d-matrix.js)|Medium|
 75|[Sort Colors](./0075-sort-colors.js)|Medium|