LeetCode 72 Edit Distance - Walkthrough

Trace Edit Distance on $s_1 = \text{"horse"}$ and $s_2 = \text{"ros"}$. Operations: insert, delete, replace. $dp[i][j]$ = min operations to transform $s_1[0..i-1]$ to $s_2[0..j-1]$. If chars match: $dp[i][j] = dp[i-1][j-1]$. Otherwise: $dp[i][j] = 1 + \min(dp[i-1][j], dp[i][j-1], dp[i-1][j-1])$.

Answer: $dp[5][3] = 3$. Operations: replace 'h' with 'r', remove 'r', remove 'e'. Or: remove 'h', replace 'r' with 'r', remove 'e'.