Company Logo Hackerrank Solution

Let’s see Company Logo Hackerrank Solution. A company wants a new logo. They want to set the letters of the logo based on the letters in their company name. They want to select 3 letters with the highest frequency in the company name. If the frequency of two letters is the same, then it should be sorted in alphabetical order.

Example

Input

aabbbccde

Output

b 3
a 2
c 2

Explanation

b is present 3 times. a, c are present 2 times, and d, e are present 1 time. So we include b first. a comes before c in alphabetical order so we include a and then we include c. 3 letters are done, so we discard the others.

Approach

First, we will need to calculate the frequency of each letter. This can be done using a dictionary in python. After that, we need to sort the values as per their frequency in descending order and their character in ascending order.

We will make use of the sorted function of python to do this. This would have been quite complicated in other languages, but Python makes it easy for us.

Let’s calculate the frequency

We check if the letter is present in the count if it is then we increment it by 1 and if it is not present we initialize it to 1.

count = {}
for val in s:
    if count.get(val):
        count[val] += 1
    else:
        count[val] = 1

Now the sorting part.

items = count.items()

This will give us a list of tuples containing a letter and their corresponding frequency

Now the most important part

items = sorted(items, key=lambda x: (x[1], -ord(x[0])), reverse=True)

We can pass sorted a function via the key argument to determine the sorting order. We are using the anonymous(lambda) function for this purpose.

lambda x: x[1] would have sorted the array by the frequency of each character. Setting reverse = True allows us to get the sorted array in descending order. But we also need to sort by the character in ascending order. Just lambda x: (x[1], x[0]) would sort characters also in descending order as the reverse is set to True. To overcome this we find the Unicode value of each character using the ord function and add a minus sign to it. The minus sign makes the value for the greatest and for z the smallest, thus it will sort in descending order which will again be reversed because of the reverse keyword and we will get the answer in ascending order.

Company Logo Hackerrank Solution in Python

s = input()
count = {}
for val in s:
    if count.get(val):
        count[val] += 1
    else:
        count[val] = 1
            
items = count.items()
items = sorted(items, key=lambda x: (x[1], -ord(x[0])), reverse=True)
for i in range(3):
    print(items[i][0], items[i][1])