I am Unable to get the with my dp solution

#1

Could You Please point out the mistake in my code I don’t want to go with the hint video I want to know whats wrong with my apporach

#2

The thing with your solution is that dp[i][j] makes no sense.
dp[a][b] should be no state.
Instead try to code a solution where dp[i][j] means that you have looked at i boxes and j of them have been taken by a.
Something like this

int dp[MAXN][MAXN];

int rec(int i, int cnt_a)
{
int cnt_b = i - cnt_a;
if(i == n) return 0;

 int &memo = dp[i][cnt_a]; 
 if(memo != -1) return memo;

 memo = 0;
 if(cnt_a < a) chkmax(memo, A[i] + rec(i + 1, cnt_a + 1));
 if(cnt_b < b) chkmax(memo, B[i] + rec(i + 1, cnt_a));

 return memo;

}