3018. Maximum Number of Removal Queries That Can Be Processed I

Think of dynamic programming.

The definition of dp is a little unusual. Try to think more.

Let dp[l][r] be the maximum number of queries we can process if we want a[l], a[l + 1], ..., a[r - 1] not to be removed after processing dp[l][r] queries.

So dp[0][n] = 0 since we can not remove anything.

The answer would be max(dp[i][i]).