Combinations of n numbers

combinations01.py

res = []
n = 3
       
def solve(size, ans):
    global res, n
    
    if size == 1 :
        for i in range(1, n + 1):
            res.append(ans + str(i))
    else:
        for i in range(1, n + 1) :
            solve(size - 1, ans + str(i) + ' ')

solve(n, "")

for i in res:
    print(i)

combinations02.py

def _increment(elements, n):
    element_off = n - 1
    while True:
        if elements[element_off] == n:
            elements[element_off] = 1
            if element_off == 0:
                return False
            element_off -= 1
        else:
            elements[element_off] += 1
            return True

def combos(n):
    assert n >= 1 and n <= 9
    elements = [1 for _ in range(n)]
    escape = False
    while not escape:
        yield ' '.join(str(i) for i in elements)
        escape = not _increment(elements, n)

for i in combos(4):
    yield i