Python: Find the largest k numbers

Last update on May 30 2025 11:49:59 (UTC/GMT +8 hours)

Find Largest K Numbers

Write a Python program to find the largest k numbers from a given list of numbers.

Input: 
[1, 2, 3, 4, 5, 5, 3, 6, 2]
Output:
[6]
Input: 
[1, 2, 3, 4, 5, 5, 3, 6, 2]
Output:
[6, 5]
Input: 
[1, 2, 3, 4, 5, 5, 3, 6, 2]
Output:
[6, 5, 5]
Input: 
[1, 2, 3, 4, 5, 5, 3, 6, 2]
Output:
[6, 5, 5, 4]
Input: 
[1, 2, 3, 4, 5, 5, 3, 6, 2]
Output:
[6, 5, 5, 4, 3]

Visual Presentation:

Sample Solution-1:

Python Code:

#License: https://bit.ly/3oLErEI
def test(nums, k):
    if k == 0:
        return []
    elif k == len(nums):
        return nums
    else:
        x = nums[0]
        for n in nums:
            if x < n:
                x = n
        result = [x]
        largest = nums[:]
        largest.remove(x)
        while len(result) != k:
            smallest = largest[0]
            for n in largest:
                if smallest < n:
                    smallest = n
            result.append(smallest)
            largest.remove(smallest)
        return result
nums = [1, 2, 3, 4, 5, 5, 3, 6, 2] 
print("Original list of numbers:",nums)
k = 1
print("Largest", k, "numbers from the said list:")
print(test(nums, k))
k = 2
print("Largest", k, "numbers from the said list:")
print(test(nums, k))
k = 3
print("Largest", k, "numbers from the said list:")
print(test(nums, k))
k = 4
print("Largest", k, "numbers from the said list:")
print(test(nums, k))
k = 5
print("Largest", k, "numbers from the said list:")
print(test(nums, k))

Sample Output:

Original list of numbers: [1, 2, 3, 4, 5, 5, 3, 6, 2]
Largest 1 numbers from the said list:
[6]
Largest 2 numbers from the said list:
[6, 5]
Largest 3 numbers from the said list:
[6, 5, 5]
Largest 4 numbers from the said list:
[6, 5, 5, 4]
Largest 5 numbers from the said list:
[6, 5, 5, 4, 3]

Flowchart:

Sample Solution-2:

Python Code:

# License: https://bit.ly/3oLErEI

# Define a function named 'test' that takes a list of numbers 'nums' and an integer 'k' as input
def test(nums, k):
    # Check if k is zero, in which case an empty list is returned
    if k == 0:
        return []
    # Check if k is equal to the length of the list, in which case the original list is returned
    elif k == len(nums):
        return nums
    else:
        # Initialize variable 'x' to the first element of the list
        x = nums[0]
        # Find the maximum element in the list and assign it to 'x'
        for n in nums:
            if x < n:
                x = n
        # Initialize a list 'result' with the maximum element as its first element
        result = [x]
        # Create a copy of the original list and assign it to 'largest'
        largest = nums[:]
        # Remove the maximum element from 'largest'
        largest.remove(x)
        # Continue adding elements to 'result' until its length becomes equal to 'k'
        while len(result) != k:
            # Find the smallest element in 'largest' and assign it to 'smallest'
            smallest = largest[0]
            for n in largest:
                if smallest < n:
                    smallest = n
            # Add the smallest element to 'result' and remove it from 'largest'
            result.append(smallest)
            largest.remove(smallest)
        return result

# Assign a specific list of numbers 'nums' to the variable
nums = [1, 2, 3, 4, 5, 5, 3, 6, 2] 

# Print a message indicating the original list of numbers
print("Original list of numbers:", nums)

# Assign a specific value 'k' to the variable
k = 1

# Print a message indicating the operation to be performed
print("Largest", k, "numbers from the said list:")
# Print the result of the test function applied to 'nums' and 'k'
print(test(nums, k))

# Assign another specific value 'k' to the variable
k = 2

# Print a message indicating the operation to be performed
print("Largest", k, "numbers from the said list:")
# Print the result of the test function applied to 'nums' and 'k'
print(test(nums, k))

# Assign another specific value 'k' to the variable
k = 3

# Print a message indicating the operation to be performed
print("Largest", k, "numbers from the said list:")
# Print the result of the test function applied to 'nums' and 'k'
print(test(nums, k))

# Assign another specific value 'k' to the variable
k = 4

# Print a message indicating the operation to be performed
print("Largest", k, "numbers from the said list:")
# Print the result of the test function applied to 'nums' and 'k'
print(test(nums, k))

# Assign another specific value 'k' to the variable
k = 5

# Print a message indicating the operation to be performed
print("Largest", k, "numbers from the said list:")
# Print the result of the test function applied to 'nums' and 'k'
print(test(nums, k))

Sample Output:

Original list of numbers: [1, 2, 3, 4, 5, 5, 3, 6, 2]
Largest 1 numbers from the said list:
[6]
Largest 2 numbers from the said list:
[6, 5]
Largest 3 numbers from the said list:
[6, 5, 5]
Largest 4 numbers from the said list:
[6, 5, 5, 4]
Largest 5 numbers from the said list:
[6, 5, 5, 4, 3]

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to return the largest k numbers from a list using sorting and slicing.
• Write a Python program to use a heap data structure to efficiently extract the k largest elements from a list.
• Write a Python program to implement a selection algorithm that finds the top k numbers without fully sorting the list.
• Write a Python program to use the nlargest() function from heapq to extract the largest k numbers from a list.

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• Python Exercises Home ↩

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Python Code Editor :

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