SDE - 1

You are given a number 'N' in the form of a string 'S', which is a palindrome. You need to find the greatest number strictly less than 'N' which is also a palindrome.

Note:

1. A palindrome is a word, number, phrase, or another sequence of characters that reads the same backward as forward, such as madam, racecar, 1234321, etc.
2. The numerical value of the given string S will be greater than 0.
3. A single-digit number is also considered a palindrome.
4. The answer number should not contain any leading zeros, except for the case when the answer is 0.
5. Note that the length of the string is nothing but the number of digits in N.

Given an array ‘ARR’ and an integer ‘K’, your task is to find all the count of all sub-arrays whose sum is divisible by the given integer ‘K’.

Note:

If there exists no subarray in the given sequence whose sum is divisible by ‘K’ then simply return ‘0’.

Example:

Suppose the given array is ‘ARR’ = { 5, 0, 2, 3, 1} and ‘K = 5’.
As we can see in below image, there are a total of 6 subarrays that have the total sum divisible by ‘K’
So we return the integer 6.

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.

You are given an array ‘ARR’ of length ‘N’ which is filled with the values such that ARR[i] = (2*i + 1). You have to perform operations on the ‘ARR’ to make all elements of the array equal. In one operation, you can choose two elements from the array ‘ARR’ say ‘i’ and ‘j’, and can increment the value of ‘ARR[i]’ by one and decrement the value of ‘ARR[j]’ by one.

You have to find the minimum number of operations to make all the elements of the array ‘ARR’ equal. It is guaranteed that all elements of the array can be made equal using some operations.

You are given two strings 'S' and 'T' of lengths 'N' and 'M' respectively. Find the "Edit Distance" between the strings.

Edit Distance of two strings is the minimum number of steps required to make one string equal to the other. In order to do so, you can perform the following three operations:

1. Delete a character
2. Replace a character with another one
3. Insert a character

Note:

Strings don't contain spaces in between.

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