Python: Find the number which when appended to the list makes the total 0

Python Programming Puzzles: Exercise-61 with Solution

Write a Python program to find the number which when appended to the list makes the total 0.

Input:
[1, 2, 3, 4, 5]
Output:
-15

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

Input:
[10, 42, 17, 9, 1315182, 184, 102, 29, 15, 39, 755]
Output:
-1316384

Pictorial Presentation:

Sample Solution:

Python Code:

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

def test(nums):
    dset = set(nums)
    result = sum(nums)
    dmin = abs(min(nums) - sum(dset^set(nums)))
    for d in dset^set(nums):
        dcopy = list(nums)
        dcopy.append(d)
        ds = sum(dcopy)
        if 0-ds < dmin:
            result = ds
            dmin = abs(ds)
        elif 0-ds == dmin:
            result = min(result, ds)
    return result*(-1)
 
nums = [1, 2, 3, 4, 5]
print("Original list of numbers:")
print(nums)
print("Number which when appended to the list makes the total 0:")
print(test(nums)) 
nums = [-1, -2, -3, -4, 5]
print("\nOriginal list of numbers:")
print(nums)
print("Number which when appended to the list makes the total 0:")
print(test(nums))  
nums = [10, 42, 17, 9, 1315182, 184, 102, 29, 15, 39, 755]
print("\nOriginal list of numbers:")
print(nums)
print("Number which when appended to the list makes the total 0:")
print(test(nums)) 

Sample Output:

Original list of numbers:
[1, 2, 3, 4, 5]
Number which when appended to the list makes the total 0:
-15

Original list of numbers:
[-1, -2, -3, -4, 5]
Number which when appended to the list makes the total 0:
5

Original list of numbers:
[10, 42, 17, 9, 1315182, 184, 102, 29, 15, 39, 755]
Number which when appended to the list makes the total 0:
-1316384

Flowchart:

Visualize Python code execution:

The following tool visualize what the computer is doing step-by-step as it executes the said program:

Python Code Editor :

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Find numbers that are adjacent to a prime number in the list, sorted without duplicates.
Next: Find the dictionary key whose case is different than all other keys.