Home
hackerrank
hackerrank certification

Usernames Changes - Problem Solving (Basic) certification | HackerRank

Statement


A company has released a new internal system, and each employee has been assigned a username. Employees are allowed to change their usernames but only in a limited way. More specifically, they can choose letters at two different positions and swap them. For example, the username “bigfish” can be changed to “gibfish” (swapping ‘b’ and ‘g’) or “bighisf” (swapping ‘f’ and ‘h’). The manager would like to know which employees can update their usernames so that the new username is smaller in alphabetical order than the original username.
For each username given, return either “YES” or “NO” based on whether that username can be changed (with one swap) to a new one that is smaller in alphabetical order. Usernames changes certification test problem | Hackerrank Solution
Note: For two different strings A and B of the same length, A is smaller than B in alphabetical order when on the first position where A and B differ, A has a smaller letter in alphabetical order than B has.
 

For example 


let’s say usernames = [“bee”, “superhero”, “ace”]. For the first username, “bee”, it is not possible to make one swap to change it to a smaller one in alphabetical order, so the answer is “NO”. For the second username, “superhero”, it is possible get a new username that is smaller in alphabetical order (for example, by swapping letters ‘s’ and ‘h’ to get “hupersero”), so the answer is “YES”. Finally, for the last username “ace”, it is not possible to make one swap to change it to a smaller one in alphabetical order, so the answer is “NO”. Therefore you would return the array of strings [“NO”. “YES”, “NO”].

Function Description


Complete the function possibleChanges in the editor below.
possible Changes has the following parameter(s): string usernames[n] an array of strings denoting the usernames of the employees Returns:
string[n]: an array of strings containing either “YES” or “NO” based on whether the username can be changed with one swap to a new one that is smaller in alphabetical order

Solution in Python:


 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
#!/bin/python3

import math
import os
import random
import re
import sys



#
# Complete the 'possibleChanges' function below.
#
# The function is expected to return a STRING_ARRAY.
# The function accepts STRING_ARRAY usernames as parameter.
#

def possibleChanges(usernames):
    ans = []
    for u in usernames:
        if len(u) <= 1:
            ans.append("NO")
        for i in range(len(u) - 1):
            if u[i] > u[i + 1]:
                ans.append("YES")
                break
        else:
            ans.append("NO")
    return ans
        
if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    usernames_count = int(input().strip())

    usernames = []

    for _ in range(usernames_count):
        usernames_item = input()
        usernames.append(usernames_item)

    result = possibleChanges(usernames)

    fptr.write('\n'.join(result))
    fptr.write('\n')

    fptr.close()
Labels : #hackerrank ,#hackerrank certification ,#problem solving ,#problem solving (Basic) ,#python ,

Post a Comment