Find all triplets i,j,k such that i+j+k=n

I’ve coded this but this is very long:

for i in range(n + 1):
    for j in range(n + 1):
        for k in range(n + 1):
            if i + j + k == n:

Is there a clever way to make it go faster? Currently it’s O(n^3) which is quite sad.

>Solution :

The innermost loop seems redundant since once you have i and j, k comes for free:

out = []
for i in range(n + 1):
    for j in range(n + 1):
        if i+j <= n:
            print((i, j, n-i-j))