#72 - Edit Distance

Medium • View on LeetCode • View on GitHub

Problem Description

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

Solution

/**
 * @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];
};