Python Nested Lists HackerRank Solution
In this tutorial, we will solve a Nested List hacker rank python problem!
Task
Given the names and grades for each student in a class of N students, store them in a nested list and print the name(s) of any student(s) having the second lowest grade.
Note: If there are multiple students with the second lowest grade, order their names alphabetically and print each name on a new line.
Example
records = [[ “chi”, 20.0]], [“beta”, 50.0], [“alpha”, 50.0]
The ordered list of scores is [20.0, 50.0], so the second lowest score is 50.0. There are two students with that score: [“beta”, “alpha”]. Ordered alphabetically, the names are printed as:
alpha
beta
Input Format
The first line contains an integer,n, the number of students.
The 2N subsequent lines describe each student over lines.
- The first line contains a student’s name.
- The second line contains their grade.
Constraints
- 2 <= N <= 5
- There will always be one or more students having the second lowest grade.
Output Format
Print the name(s) of any student(s) having the second lowest grade in. If there are multiple students, order their names alphabetically and print each one on a new line.
Sample Input 0
5
Harry
37.21
Berry
37.21
Tina
37.2
Akriti
41
Harsh
39
Sample Output 0
Berry
Harry
Explanation 0
There are 5 students in this class whose names and grades are assembled to build the following list:
python students = [[‘Harry’, 37.21], [‘Berry’, 37.21], [‘Tina’, 37.2], [‘Akriti’, 41], [‘Harsh’, 39]]
The lowest grade of 37.2 belongs to Tina. The second lowest grade of 37.21 belongs to both Harry and Berry, so we order their names alphabetically and print each name on a new line.
Solution:
if __name__ == '__main__':
alist = []
for i in range(int(input())):
name = input()
score = float(input())
alist.append([name, score])
second_highest = sorted(set([score for name, score in alist]))[1]
print('\n'.join(sorted([name for name, score in alist if score == second_highest])))
Steps Used in solving the problem -
Step 1: First we created an empty list.
Step 2: then we created a loop that will also take input of the total number of students.
Step 3: After this, we have taken the input of names and scores inside our loop.
Step 4: After this, we sorted our list and converted it into a set. And we have also used list comprehension in which score is our output and we have used for loop after this.
Step 5: In the last step, we used another list comprehension in which the name is our output and we used for loop after this with if condition. Here, ‘\n’.join will print the names in different lines.
