LeetCode 72 Edit Distance - Operations

You have three operations at each step:

$1.$ Insert: Add a character to A. Moves from $(i, j)$ to $(i, j-1)$ in DP (you matched B[j] by inserting).

$2.$ Delete: Remove a character from A. Moves from $(i, j)$ to $(i-1, j)$ (discarded A[i]).

$3.$ Replace: Change a character in A. Moves from $(i, j)$ to $(i-1, j-1)$ (aligned A[i] with B[j]). Each operation costs 1. If characters match, no operation needed.