SDE - 1

There are ‘N’ people numbered from 0 to N - 1, standing in a queue. You are given two arrays ‘Height’ and ‘Infront‘ consisting of ‘N’ non-negative integers. ‘Height[i]’ gives the height of the ith person, and ‘Infront[i]’ gives the number of persons who are taller than the ith person and standing in front of the ith person.

Your task is to find out the actual order of people in a queue. You should print ‘N’ integers where the ‘ith’ integer is the height of the person who should be at the ith position from the start of the queue.

Note :

1. Consider that all elements in array ‘Height’ are unique.
2. It is guaranteed that a valid order always exists for the given array ‘Height’ and ‘Infront’. 

Example :

Let there are 6 people, their heights are given by array  ‘Height’ :  [5, 3, 2, 6, 1, 4],  and the number of people in front of them is given by array ‘Infront’: [0, 1, 2, 0, 3, 2]

Thus the actual order of people’s height in the queue will be [5, 3, 2, 1, 6, 4]

In this order, the first person in a queue i.e a person with a height of 5, has no person in front of them who is taller than him.
The second person in a queue i.e a person with a height of 3 has 1 person (person with height 5) in front of them who is taller than him.
The third person in a queue i.e a person with a height of 2 has 2 people (people with height 5 and 3) in front of them who are taller than him.
The fourth person in a queue i.e a person with a height of 1 has 3 people (people with height 5, 3, 2) in front of them who are taller than him.
The fifth person in a queue i.e a person with a height of 6 has no person in front of them who is taller than him.
The sixth person in a queue i.e a person with a height of 4 has 2 people (people with height 5, and 6) in front of them who are taller than him.

We can observe this is the only possible order that is possible according to the array ‘Infront’.

Given an array of size 'N' return the count array such that COUNT[i] equals the number of element which are smaller than ARR[ i ] on its the right side.

For Example : ARR = [4,2,1,5] the count array corresponding to the given array is :-.

The Number of elements smaller than 4 on its right side is 2.
The Number of elements smaller than 2 on its right side is 1.
The Number of elements smaller than 1 on its right side is 0.
The Number of elements smaller than 5 on its right side is 0.
Hence the count array is [2,1,0,0]

There was code of in-place merge sort in a linked list and there were a few bugs in it both logical and optimisation ones. We needed to correct them.

You are given a ternary expression in the form of a string. Your task is to convert this expression into a binary tree.

Note:

1. The string is made up of lowercase English alphabets,  ‘?’ and ‘:’ special characters.

2. The alphabets may be repeated in the string.

3. The expression which uses ‘?:’ is known as ternary expression and the expression will be evaluated as (condition ? value_if_true : value_if_false).

Given a string ‘strNum’ which represents a number, your task is to find the ways to decode the given string ‘strNum’.

The format of encoding is as follows: ‘A’ - 1, ‘B’ - 2, ‘C’ - 3, ‘D’ - 4, ……………, ‘Z’ - 26.

Encoding is possible in letters from ‘A’ to ‘Z’. There is an encoding between character and number.

Example :

‘n = 226’ so we can decode ‘226’ in such a way-

‘BZ = 2-26’, as B maps to 2 and Z maps to 26.

‘BBF = 2-2-6’

‘VF = 22-6’

‘226; can be decoded in three ‘BZ’, ‘BBF’, ‘VF’ possible ways.

Point to be noticed we can’t decode ‘226’ as ‘226’ because we have no character which can directly map with ‘226’ we can only decode numbers from ‘1’ to ‘26’ only.