Specialist Programmer

You are given a string (STR) of length N, consisting of only the lower case English alphabet.

Your task is to remove all the duplicate occurrences of characters in the string.

For Example:

If the given string is:
abcadeecfb

Then after deleting all duplicate occurrences, the string looks like this:
abcdef

You are given a list of “N” strings A. Your task is to check whether you can form a given target string using a combination of one or more strings of A.

Note :

You can use any string of A multiple times.

Examples :

A =[“coding”, ”ninjas”, “is”, “awesome”]  target = “codingninjas”
Ans = true as we use “coding” and “ninjas” to form “codingninjas”

You have been given a string STR. Your task is to find the total number of palindromic substrings of STR.

Example :

If the input string is "abbc", then all the possible palindromic substrings would be: ["a", "b", "b", c", "bb"] and hence, the output will be 5 since we have 5 substrings in total which form a palindrome.

Note :

A string is said to be a 'Palindrome' if it is read the same forwards and backwards. 
For example, “abba” is a palindrome, but “abbc” is not.

A 'Substring' is a contiguous sequence of characters within a string. 
For example, "a", "b", "c", "ab", "bc", "abc" are substrings of "abc".