AppDynamics Interview Question

1. Longest substring palindrome from a string 2.Generate parentheses Input -- n=1 output -- () Input -- n=2 output -- ()() (()) 3.input -- (A, D), (B, E), (F, G), (D, P) (P, O) (L, A) Apple Output -- true Only one character from each set to from the word 4. Find the missing number from an consecutive numbers of array input -- {1,2,3,5,} output -- 4