Itroduction to Sets – Python Hackerrank Solution

Problem:Introduction Of Sets – Python Hackerrank Solution

Introduction to Sets

set is an unordered collection of elements without duplicate entries.
When printed, iterated, or converted into a sequence, its elements will appear in an arbitrary order.


>>> print set()

>>> print set('HackerRank')
set(['a', 'c', 'e', 'H', 'k', 'n', 'r', 'R'])

>>> print set([1,2,1,2,3,4,5,6,0,9,12,22,3])
set([0, 1, 2, 3, 4, 5, 6, 9, 12, 22])

>>> print set((1,2,3,4,5,5))
set([1, 2, 3, 4, 5])

>>> print set(set(['H','a','c','k','e','r','r','a','n','k']))
set(['a', 'c', 'r', 'e', 'H', 'k', 'n'])

>>> print set({'Hacker' : 'DOSHI', 'Rank' : 616 })
set(['Hacker', 'Rank'])

>>> print set(enumerate(['H','a','c','k','e','r','r','a','n','k']))
set([(6, 'r'), (7, 'a'), (3, 'k'), (4, 'e'), (5, 'r'), (9, 'k'), (2, 'c'), (0, 'H'), (1, 'a'), (8, 'n')])

Basically, sets are used for membership testing and eliminating duplicate entries.


Now, let’s use our knowledge of sets and help Mickey.

Ms. Gabriel Williams is a botany professor at District College. One day, she asked her student Mickey to compute the average of all the plants with distinct heights in her greenhouse.

Formula used:

Average=Sum of Distinct Heights/Total Number of Distinct Heights

Function Description

Complete the average function in the editor below.

average has the following parameters:

  • int arr: an array of integers


  • float: the resulting float value rounded to 3 places after the decimal

Input Format

The first line contains the integer,N , the size of arr.
The second line contains the N space-separated integers,arr[i] .



Sample Input

STDIN                                       Function
-----                                       --------
10                                          arr[] size N = 10
161 182 161 154 176 170 167 171 170 174     arr = [161, 181, ..., 174]

Sample Output



Here, set([154,161,167,170,171,174,176,182])is the set containing the distinct heights. Using the sum() and len() functions, we can compute the average.Change



#Itroduction to Sets - Python Hackerrank Solution
def average(array):
    # your code goes here
    return float(sum(set(array))/len(set(array)))

#Itroduction to Sets - Python Hackerrank Solution

Disclaimer: This problem is originally created and published by HackerRank, we only provide solutions to this problem. Hence, doesn’t guarantee the truthfulness of the problem. This is only for information purposes.

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