How Do I Perform a Binary Search Within a Nested List?

Question

The question is:

In a class, the physical education teacher recorded the height of the students.

For a sports meet, he has to create a list of the students according to the heights in ascending order. Then he needs to find the person of a height greater or equal to 58 inches to select for a particular sport.

Note: Use Selection sort to sort the students and Binary search to search the students in that list.

Write the PAC, algorithm, and python code to implement the same.

INPUT:

Enter the number of students N
For each N student 
Enter the regno.
Enter the height.

OUTPUT:

List of students’ Reg numbers (sorted in order of height)
Register no of the students having height greater than or equal to 58 inches / NOT FOUND

What I did so far:

D=[]
n = int(input("enter number of students:"))

for i in range(0, n):
    regno=input('enter registration number: ')
    height=int(input('enter hieght of student: '))
    D.append(['regno' , regno, 'height' , height])

D.sort(key=lambda x: x[3])

Now what?

Answer 1

According to me the question is not quite right , because it is asking to perform a binary sort to find heights above or equal to 58 . A binary sort will only work if a person with a height of 58 inches is present , cuz in that case we can precisely get the index of element that contains the height 58 . But if the height 58 is not present i.e. if people with height 59,60,61... are present , binary search will not work. Here is my solution building on your approach:

D=[]
n = int(input("enter number of students:"))

# entering the required data to the lists
for i in range(0, n):
    regno=input('enter registration number: ')
    height=int(input('enter height of student: '))
    D.append(['Regno:',regno,'Height:', height])

# performing selection sort (in ascending order)

for step in range(len(D)):
        min_id = step
        for i in range(step + 1, len(D)):
         
            if D[i][3] < D[min_id][3]:
                min_id = i
        (D[step], D[min_id]) = (D[min_id], D[step])

#comparing the heights of the students to find the index of the student whose height is nearest to 58 .

for i in range(len(D)):
    if D[i][3]<58:
        continue
    elif D[i][3] >=58:
        index=i
        break
# once we get the index of the student whose height is the nearest to 58 , we use list slicing to display the records starting from that index.
print("The list of students whose height greater than or equal to  58 inches:")
print(D[index:])