1mg Interview Experience (Off Campus)

I was interviewed for Software Developer Profile at 1mg, gurugram.

Round 1: Online Test

• Given an array of numbers, arrange them in a way that yields the largest value.
  For example, if the given numbers are {54, 546, 548, 60}, the arrangement 6054854654 gives the largest value. And if the given numbers are {1, 34, 3, 98, 9, 76, 45, 4}, then the arrangement 998764543431 gives the largest value.
• We have to find the count of Longest increasing subsequence (LIS) for each change we made at i^th position in array from 1 to n, i.e 1<=a[i]<=n.
  – Input:
  3 1               // n  i
  1 2 3
  – Output:
  2         //LIS of  1 1 3    put a[i]=1
  3        // LIS of  1 2 3     put a[i]=2
  2        //LIS of  1 3 3     put a[i]=3
  – Time Complexity Required: O(nlogn)+O(n)

Round 2:

• Tell me about yourself.
• Current project in the current organization
  – REST VS SOAP
  – HTTP Methods of REST
  – Write a REST service to search a particular data in Database in current project.
• Design an Authentication system (with only email ans password)(with flow and Database Schema).
• Design a Third party Authentication system via Facebook(with flow and Database Schema).

Round 3:

• Discussion on College Project based on Machine learning ( explain KNN- classifier )

• Find the minimum element in a sorted and rotated array
  Input: {5, 6, 1, 2, 3, 4}
  Output: 1

• To find maximum length substring in an input string which could be arranged into a palindrome, only even length palindromes are expected. Input is one line String which contains only integers.
  The output is the length of the substring which could be arranged in palindrome.
  Input: 124565463
  Output: 6 (substring 456546 can be rearranged to an even palindrome)
• In 1D number line system (-Infinity, +Infinity), at beginning a car with velocity(V)=+1 at position(pos)=0 (origin), with every Acceleration(A) it jumps twice of its current velocity(in +ve or -ve direction) and with every Reverse(R) it’s position remain same but velocity changes to -1 if its was +ve or +1 if it was -ve.
  You have to find the count of shortest string (combination of A’s and R’s) to reach from origin to +N
  Input: +6
  Output: 5 (substring AAARA )
  Explanation:  pos      V
  Initial :           0        +1
  after A:         +1        +2
  after A:         +3       +4
  after A:         +7        +8
  after R:         +7         -1
  after A:         +6        -2

• Implement rand3() using rand2()

• Implement rand5() using rand2()

Round 4:

• Given an array of n elements which contains elements from 0 to n-1, with any of these numbers appearing any number of times. Find these repeating numbers in O(n) and using only constant memory space.
  For example, let n be 7 and array be {1, 2, 3, 1, 3, 6, 6}, the answer should be 1, 3 and 6.
• Given an unsorted array of n integers which can contain integers from 1 to n. Some elements can be repeated multiple times and some other elements can be absent from the array.Count frequency of all elements .
  Input: arr[] = {2, 5, 3, 2, 5}
  Output: Below are frequencies of all elements
  1 -> 0
  2 -> 2
  3 -> 1
  4 -> 0
  5 -> 2

• A program to check if a binary tree is BST or not

• What happens when you type google.com in the browser (with network flow) ?

• Computer network concepts

Round 5: VP round

• Tell me about yourself.
• Current project in the current organization
  – What was the toughest challenge you faced in a project?
• Why do you want to leave current organisation
• Print characters and their frequencies( special characters can be present).
  Input : str = “$characters$”
  Output : $2 c2 h1 a2 r2 t1 e1 s1
  Hint: Hash, AVL

Got Offer but declined as I had better option, not in terms of money but in tech. stack