HackerRank Nested Lists problem solution in Python | Hacker Rank Python Question Solution

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.

 

Problem solution in Python 2 programming.

n = int(raw_input())
lst = []
for x in range(0, n):
    lst.append([raw_input(), float(raw_input())])
lst = sorted(lst, key=lambda x: x[1]);
for x in range(1, n):
    if(lst[x][1] != lst[x-1][1]):
        score = lst[x][1]
        break
lst = sorted(lst);
for x in range(n):
    if(lst[x][1] == score):
        print lst[x][0]

Problem solution in Python 3 programming.

if __name__ == '__main__':
    students = []
    for _ in range(int(input())):
        name = input()
        score = float(input())
        students.append([name,score]) 
    x = 99999
    for i in range(len(students)):
        if x > float(students[i][1]):
            x = float(students[i][1])
    y = 999999
    for i in range(len(students)):
        if float(students[i][1]) > float(x) and y > float(students[i][1]):
            y = float(students[i][1])
    runner = []
    for i in range(len(students)):
        if float(students[i][1]) == float(y):
            runner.append(students[i][0])
    runner = sorted(runner)

    for i in range(len(runner)):
        print(runner[i])

Problem solution in pypy programming.

if __name__ == '__main__':
    L=[]
    n=int(raw_input())
    for _ in range(n):
        name = raw_input()
        score = float(raw_input())
        L.append([name,score])
    k=[]
    for i in range(n):
        k.append(L[i][1])
    k.sort()
        
    i=1
    while i<n and k[0]==k[i]:
        i=i+1
    m=k[i]
    s=[]
    for j in range(n):
        if L[j][1]==m:
            s.append(L[j][0])
    s.sort()
    for z in range(len(s)):
     print(s[z])

Problem solution in pypy3 programming.

if __name__ == '__main__':
   
    arr = []
    for _ in range(int(input())):
        name = input()
        score = float(input())       
        arr.append([score,name])
    arr.sort()
    for i in range(len(arr)):
         if arr[i][0]> arr[0][0]:
            print(arr[i][1])
            
            if i+1 >= len(arr) or arr[i+1][0] > arr[i][0]:
                #print(arr[i+1][1])
                break    
    #print (arr[1][1])
        #print (arr)
        #print (x)