How to generate a n-sized random float array that sums up to 0.0?

Consider that a need a n-sized vector where each element is defined between [-1,1]. The element a[i] is a float generated by -1 + 2*rand(). I need a elegant way to ensure that the sum of the elements of my array is equal to zero.

I've found two possible solutions:

The first one is this matlab function https://www.mathworks.com/matlabcentral/fileexchange/9700-random-vectors-with-fixed-sum. It has also a implementation in R, however it is too much work to implement it on C, since this function is used for a 2d array.

The second one is provided in this thread here: Generate random values with fixed sum in C++. Essentially, the idea is to generate n numbers with a normal distribution then normalize them to with my sum. (I have implemented it using python bellow) for a vector with sum up to 1.0. It works for every sum value except for zero.

import random as rd

mySum = 1;
randomVector = []
randomSum = 0

for i in range(7):
    randomNumber = -1 + 2*rd.random()
    randomVector.append(randomNumber)
    randomSum  += randomNumber

coef = mySum/randomSum
myNewList = [j * coef for j in randomVector]
newsum = sum(myNewList)

So, is there a way to do that using C or C++? If you know a already implemented function it would be awesome. Thanks.