#583 - Delete Operation for Two Strings

Medium • View on LeetCode • View on GitHub

Problem Description

Given two strings word1 and word2, return the minimum number of steps required to make word1 and word2 the same.

In one step, you can delete exactly one character in either string.

Solution

/**
 * @param {string} word1
 * @param {string} word2
 * @return {number}
 */
var minDistance = function(word1, word2) {
  const dp = new Array(word1.length + 1).fill().map(() => {
    return new Array(word2.length + 1).fill(0);
  });

  for (let i = 1; i <= word1.length; i++) {
    dp[i][0] = i;
  }
  for (let j = 1; j <= word2.length; j++) {
    dp[0][j] = j;
  }
  for (let i = 1; i <= word1.length; i++) {
    for (let j = 1; j <= word2.length; j++) {
      dp[i][j] = word1[i - 1] === word2[j - 1]
        ? dp[i - 1][j - 1]
        : Math.min(dp[i - 1][j], dp[i][j - 1]) + 1;
    }
  }

  return dp[word1.length][word2.length];
};