Python collections.Counter() HackerRank Solution
collections.Counter()
A counter is a container that stores elements as dictionary keys, and their counts are stored as dictionary values.
Sample Code
>>> from collections import Counter
>>>
>>> myList = [1,1,2,3,4,5,3,2,3,4,2,1,2,3]
>>> print Counter(myList)
Counter({2: 4, 3: 4, 1: 3, 4: 2, 5: 1})
>>>
>>> print Counter(myList).items()
[(1, 3), (2, 4), (3, 4), (4, 2), (5, 1)]
>>>
>>> print Counter(myList).keys()
[1, 2, 3, 4, 5]
>>>
>>> print Counter(myList).values()
[3, 4, 4, 2, 1]
Task
Raghu is a shoe shop owner. His shop has X number of shoes.
He has a list containing the size of each shoe he has in his shop.
There are N number of customers who are willing to pay xi amount of money only if they get the shoe of their desired size.
Your task is to compute how much money Raghu earned.
Input Form at
The first line contains X, the number of shoes.
The second line contains the space-separated list of all the shoe sizes in the shop.
The third line contains N, the number of customers.
The next N lines contain the space-separated values of the shoe size desired by the customer and xi, the price of the shoe.
Constraints
0 < X < 10^3
0 < N <= 10^3
20 < xi < 100
2 < shoe size < 20
Output Format
Print the amount of money earned by Raghu.
Sample Input
10
2 3 4 5 6 8 7 6 5 18
6
6 55
6 45
6 55
4 40
18 60
10 50
Sample Output
200
Explanation
-
Customer 1: Purchased size 6 shoe for $55.
-
Customer 2: Purchased size 6 shoe for $45.
-
Customer 3: Size 6 no longer available, so no purchase.
-
Customer 4: Purchased size 4 shoe for $40.
-
Customer 5: Purchased size 18 shoe for $60.
-
Customer 6: Size 10 not available, so no purchase.
Total money earned = 55 + 45 + 40 + 60 = $200
Solution:
from collections import Counter
x = int(input())
y = Counter(map(int, input().split()))
z = int(input())
total = 0
for i in range(z):
size, rate = map(int, input().split())
if y[size]:
y[size] -= 1
total += rate
print(total)
Steps Used in solving the problem -
Step 1: First we imported the counter from collections.
Step 2: then we have taken the input of x i.e, the total number of shoes.
Step 3: and we have taken the input of y i.e, the list of all shoe sizes. Then we used counter to arrange our list as a dictionary.
Step 4: we’ve also taken the input of z i.e, the total number of customers.
Step 5: then we created a variable to store the total.
Step 6: then we created a for loop in the range of z(total number of customers)
Step 7: inside for loop, we have taken the input of size and rate from each customer. Then we used an if condition to verify the input size is in y.
Step 8: then we added all the rates in our total and printed it.
