MAY-31 2020 Challenge

Edit Distance

Given two words word1 and word2, find the minimum number of operations required to convert word1 to word2.

You have the following 3 operations permitted on a word:

1. Insert a character
2. Delete a character
3. Replace a character

Example 1:

Input: word1 = "horse", word2 = "ros"
Output: 3
Explanation: 
horse -> rorse (replace 'h' with 'r')
rorse -> rose (remove 'r')
rose -> ros (remove 'e')

Example 2:

Input: word1 = "intention", word2 = "execution"
Output: 5
Explanation: 
intention -> inention (remove 't')
inention -> enention (replace 'i' with 'e')
enention -> exention (replace 'n' with 'x')
exention -> exection (replace 'n' with 'c')
exection -> execution (insert 'u')

Solution in Java :

class Solution {
public int minDistance(String word1, String word2) {
int m = word1.length(), n = word2.length();

int[][] dp = new int[m + 1][n + 1];

for(int i = 0; i <= m; i++) {
dp[i][0] = i;
}
for(int j = 0; j <= n; j++) {
dp[0][j] = j;
}

for(int i = 1; i <= m; i++) {
for(int j = 1; j <= n; j++) {
if(word1.charAt(i - 1) == word2.charAt(j - 1))
dp[i][j] = dp[i - 1][j - 1];
else
dp[i][j] = min(dp[i - 1][j - 1] + 1, dp[i - 1][j] + 1, dp[i][j - 1] + 1);
}
}
return dp[m][n];
}

private int min(int a, int b, int c) {
if(a <= b && a <= c) return a;
else if (b <= a && b <= c) return b;
else return c;
}
}

Comments

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