I have solved all these questions before. Will be able to do it. I have gone through the pdf. Here is my understanding about the same.
DP.
Part1: You make a table of n*m. Now, dp[n][m] = min(dp[n][m-1],dp[m-1][n]) is last chars are not same, else dp[n-1][m-1]. Now this can be done
Part2: I can tell you this on chat. A similar dp.
Greedy: We can discuss this on the chat as well.
You can trust me completely about this project. I will complete it as soon as possible