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Last Updated: 21 May, 2021

Party Over

eBayWatchGuard Technologies

Problem statement

Ninja is coming after a long party to his home, but he faces a monster while returning. Monster puts up a condition to Ninja in order to free him. The monster gives him ‘n’ strings and asks him to sort them. However, he adds an extra condition to him.

Since the monster knows that Ninja could do it easily, the monster wants him to sort them using the last letter of each string. If there are strings with the same last character, sort them based on their second last character and so on.

Ninja gets totally confused, he asks you to solve the problem. Can you help Ninja figure out the correct order of strings?

Input Format:
The first line of input contains an integer ‘T,’ denoting the number of test cases. The test cases follow.

The first line of each test case contains a number ‘n’ denoting the number of strings.

The second line of each test case contains ‘n’ space-separated strings that the monster gave to Ninja.
Output Format:
For each test case, print the strings sorted according to the last character.

Print the output of each test case in a separate line.
You are not required to print the expected output; it has already been taken care of. Just implement the function.
1 <= T <= 10
1 <= n <= 10^3
1 <= size of string <= 10^2

Where 'T’ is the number of test cases, ‘n’ denotes the number of strings

Time Limit: 1 sec


01 Approach

The idea is to reverse all the strings and then sort them in alphabetical order and return the sorted strings back in their original form. We can use a nested loop and compare each string with all the preceding strings to sort the strings.


The steps are as follows:

  • Initially, input a string array “arr” containing all the strings needed to be sorted based on the last character.
  • Reverse the array containing all the strings using the in-built reverse() function.
  • We will apply a nested loop with the outer loop pointed by ‘i’ starting from 0 and going till ‘n’ - 1 where ‘n’ is the number of strings in the array and the inner loop pointed by j=i+1 and going till ‘n.’
  • Now we will start comparing the strings arr[i] and arr[j] using the relational operators.
  • We will check if the compare() function returns a value greater than 0. If it does, then we can be sure that arr[i] is lexicographically more significant than the string arr[j].
  • Hence swap both strings using the in-built swap function.
  • After the swapping operation is performed, reverse back all the strings in their original form.
  • We will return the array containing all the strings as the answer.