Python: Sum of the magnitudes of the elements in the array with product signs

Last update on May 30 2025 11:48:57 (UTC/GMT +8 hours)

Signed Sum of Magnitudes

Write a Python program to find the sum of the magnitudes of the elements in the array. This sum should have a sign that is equal to the product of the signs of the entries.

Input:
[1, 3, -2]
Output:
-6

Input:
[1, -3, 3]
Output:
-7

Input:
[10, 32, 3]
Output:
45

Input:
[-25, -12, -23]
Output:
-60

Visual Presentation:

Sample Solution:

Python Code:

# Define a function named 'test' that takes a list of numbers as a parameter
def test(nums):
    # Calculate the total sum of the magnitudes of the elements in the array
    tot = sum(abs(i) for i in nums)
    
    # Check if all elements in the array are non-zero
    if all(nums):
        # Return the total sum with a positive or negative sign based on the product of the signs of the entries
        return tot if sum(i < 0 for i in nums) % 2 == 0 else -tot
    # If there is a zero element in the array, return 0
    return 0

# Set a list of numbers as the input for the test function
nums = [1, 3, -2]
# Print a message indicating the original list of numbers
print("Original list of numbers:")
# Print the original list of numbers
print(nums)
# Print a message indicating the task and the result of the test function
print("Sum of the magnitudes of the elements in the array with a sign that is equal to the product of the signs of the entries:")
# Print the result of the test function applied to the given list of numbers
print(test(nums))

# Set a new list of numbers as the input for the test function
nums = [1, -3, 3]
# Print a message indicating the original list of numbers
print("\nOriginal list of numbers:")
# Print the original list of numbers
print(nums)
# Print a message indicating the task and the result of the test function
print("Sum of the magnitudes of the elements in the array with a sign that is equal to the product of the signs of the entries:")
# Print the result of the test function applied to the new list of numbers
print(test(nums))

# Set another new list of numbers as the input for the test function
nums = [10, 32, 3]
# Print a message indicating the original list of numbers
print("\nOriginal list of numbers:")
# Print the original list of numbers
print(nums)
# Print a message indicating the task and the result of the test function
print("Sum of the magnitudes of the elements in the array with a sign that is equal to the product of the signs of the entries:")
# Print the result of the test function applied to the new list of numbers
print(test(nums))

# Set yet another new list of numbers as the input for the test function
nums = [-25, -12, -23]
# Print a message indicating the original list of numbers
print("\nOriginal list of numbers:")
# Print the original list of numbers
print(nums)
# Print a message indicating the task and the result of the test function
print("Sum of the magnitudes of the elements in the array with a sign that is equal to the product of the signs of the entries:")
# Print the result of the test function applied to the new list of numbers
print(test(nums))

Sample Output:

Original list of numbers:
[1, 3, -2]
Sum of the magnitudes of the elements in the array with a sign that is equal to the product of the signs of the entries:
-6

Original list of numbers:
[1, -3, 3]
Sum of the magnitudes of the elements in the array with a sign that is equal to the product of the signs of the entries:
-7

Original list of numbers:
[10, 32, 3]
Sum of the magnitudes of the elements in the array with a sign that is equal to the product of the signs of the entries:
45

Original list of numbers:
[-25, -12, -23]
Sum of the magnitudes of the elements in the array with a sign that is equal to the product of the signs of the entries:
-60

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to compute the sum of absolute values of a list and then assign the overall sign based on the product of the original signs.
• Write a Python program to separate positive and negative numbers, sum their magnitudes, and multiply by -1 if an odd number of negatives exists.
• Write a Python program to use functional programming to calculate the signed sum where the sign is determined by the product of signs.
• Write a Python program to iterate over a list, sum the absolute values, and then adjust the final result’s sign based on the cumulative sign product.

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Python Code Editor :

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