paytm visited my college nit xxx in december 2020 .
there were total 4 rounds . 1 coding + 3 technical rounds .
CTC was 9 lpa (8+1) while intern stipend was 20k .

In coding round , there were 3 questions and we had to write code . questions were easy .

technical 1 -

• what is virtual memory .
• diffrence b/w tcp and udp .
• find loop in linked list and remove it .
• puzzle - there are total 10 coins . 5 having tail up and 5 having head up .we can not see them but we can flip them any no. of times . now we have to make two piles , each with same no. of tails up . how can we make without seeing them but can flip them ?
• puzzle - we have 2 ropes , each takes 60 minutes in burning if we burn them from one end. we have to calculate 45 minutes . ( we can not bend the rope ) .
• then he asked me to discuss project . I did project on image classification , so he asked some questions related to machine learning .

technical 2

• discuss oops concepts .

• write code for multiple inheritence ( 2 base classes and 1 child ) . what is the order of constructer and destructor calling .

• implement stack using queues .

• An ascending sorted array is given. find kth missing number in O(1) space complexity. if kth missing no. do not exist then return -1.
  arr=[ 5,6,9,11,19 ] , k=6
  output : 14

  arr=[2,3,4,6,8] ,k=3
  output : -1

technical 3 -

• she - we have to perform 3 operations insert data , delete data , find data . which data structure you prefer to use and why ?
  I - map
  she - why ?
  I - because it uses binary search .
  she - why not binary search tree .
  I - beacuse if tree will be skewed then it may take O(n) time .

• what is process synchronisation .

• discuss different cpu scheduling algorithms .

• discuss producer-consumer problem .

• print a binary tree in spiral order.

            1
   		  /    \
   	     2      3
   	    / \    / \
   	   4   5  6   7
   	  /      /
   	 8      9

	output - 1 3 2 4 5 6 7 9 8

• puzzle - there are 3 jars . one has apples , other has oranges and other one has apple + oranges . all are mislablled . none of the jar is correctly lablled . minimum no. of fruits we have to pickup to label them correctly .
• we can encode 1 to a, 2 to b ..........and 26 to z . find the total possible encodings for a given number .
  eg . input = 123 , output - 3 (abc,aw,lc)
  eg . input = 426 , output - 2 (dbf,dz)

total 18 were selected . (14 (intern + fte) and 4 intern ) and i was one among them with intern + fte . thanks to leetcode because most of questions they asked were seen for me and I had already solved on leetcode .