SDE - Intern

Reverse the given string word wise. That is, the last word in given string should come at 1st place, last second word at 2nd place and so on. Individual words should remain as it is.

After years of research, Ninja is finally able to invent the time machine, and now he is back to the good old days when T9 keypads were being used in mobile phones.

Being a curious person, Ninja wants to find out all possible strings that can be formed by pressing the keys of the phone.

Formally, you are given a string S, that consists of digits from 2-9 (both inclusive), your task is to find out all the possible strings that can be formed from the input string by mapping the digits to the letters as in a T9 keypad. Then, print the strings in a lexicographically sorted order.

For Example:

If S = “34”, then all the possible letters that can be formed from string S are {“dg”, “dh”, “di”, “eg”, “eh”, “ei”, “fg”, “fh”, “fi”}.

You are given an integer N, you need to find the number of trailing zeroes in N! (N factorial).

Note:

1. Trailing zeros in a number can be defined as the number of continuous suffix zeros starting from the zeroth place of a number.
2. For example, if a number X = 1009000, then the number of trailing zeros = 3 where the zeroth place is 0, the tenth place is 0, the hundredth place is 0.
3. ! means “FACTORIAL”. Factorial of a number is calculated by the product of the integer and all integers below it till 1.
4. Value of 0! is 1.

You are given an 'N * N' matrix of integers where each row and each column is sorted in increasing order. You are given a target integer 'X'.

Find the position of 'X' in the matrix. If it exists then return the pair {i, j} where 'i' represents the row and 'j' represents the column of the array, otherwise return {-1,-1}

For example:

If the given matrix is:
[ [1, 2, 5],
  [3, 4, 9],
  [6, 7, 10]] 
We have to find the position of 4. We will return {1,1} since A[1][1] = 4.

You are given an array of ‘N’ integers say ‘ARR’ and provided with other integer say ‘K’. Now you have to find the Rank of ‘ARR[K]’.

Note:

The rank of any element in ‘ARR’ is equal to the number of smaller elements than ‘ARR[K]’ on its left side.

For example :

Input :
Let ‘ARR’’ = [6, 2, 9, 7] and ‘X’ = 3.
We can see there are two smaller elements than ‘ARR[3]’ = 7 on its left side
Output: 2

Follow Up :

Try to find rank in less time complexity than O(N), you may use some data structure to implement this.

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