Developer Associate

You are given a string denoting a valid Postfix expression containing ‘+’, ’-’, ’*’, ‘/’ and lowercase letters.

Convert the given Postfix expression into a Prefix expression.

Note:

Postfix notation is a method of writing mathematical expressions in which operators are placed after the operands. For example, "a b +" represents the addition of a and b.

Prefix notation is a method of writing mathematical expressions in which operators are placed before the operands. For example, "+ a b" represents the addition of a and b.

Expression contains lowercase English letters, ‘+’, ‘-’, ‘*’, and  ‘/’. 

Example:

Input: abc*+

Output: +a*bc

Explanation:
For the given postfix expression, infix expression is a+b*c. And it's corresponding prefix expression is +a*bc.

You are given an infinite supply of coins of each of denominations D = {D0, D1, D2, D3, ...... Dn-1}. You need to figure out the total number of ways W, in which you can make a change for value V using coins of denominations from D. Print 0, if a change isn't possible.

You are given a string ('STR') of length 'N'. Find the longest palindromic substring. If there is more than one palindromic substring with the maximum length, return the one with the smaller start index.

Note:

A substring is a contiguous segment of a string.

For example : The longest palindromic substring of "ababc" is "aba", since "aba" is a palindrome and it is the longest substring of length 3 which is a palindrome, there is another palindromic substring of length 3 is "bab" since "aba" starting index is less than "bab", so "aba" is the answer.

Basic os theory questions + simple SQL concepts like normal forms, joins etc

Hr question like why sap, where do you look yourself after 5 years etc