# -----------------------------------------------------------------------------

# From Numpy to Python

# Copyright (2017) Nicolas P. Rougier - BSD license

# More information at https://github.com/rougier/numpy-book

# -----------------------------------------------------------------------------

import numpy as np

import itertools as it

def solution_1():

# Author: Tucker Balch

# Brute force

# 14641 (=11*11*11*11) iterations & tests

Z = []

for i in range(11):

for j in range(11):

for k in range(11):

for l in range(11):

if i+j+k+l == 10:

Z.append((i,j,k,l))

return Z

def solution_2():

# Author: Daniel Vinegrad

# Itertools

# 14641 (=11*11*11*11) iterations & tests

return [(i,j,k,l)

for i,j,k,l in it.product(range(11),repeat=4) if i+j+k+l == 10]

def solution_3():

# Author: Nick Poplas

# Intricated iterations

# 486 iterations, no test

return [(a, b, c, (10 - a - b - c))

for a in range(11) for b in range(11 - a) for c in range(11 - a - b)]

def solution_3_bis():

# Iterator using intricated iterations

# 486 iterations, no test

return ((a, b, c, (10 - a - b - c))

for a in range(11) for b in range(11 - a) for c in range(11 - a - b))

def solution_4():

# Author: Yaser Martinez

# Numpy indices

# No iterations, 1331 (= 11*11*11) tests

X123 = np.indices((11,11,11)).reshape(3,11*11*11)

X4 = 10 - X123.sum(axis=0)

return np.vstack((X123, X4)).T[X4 > -1]

if __name__ == '__main__':

from tools import timeit

timeit("solution_1()", globals())

timeit("solution_2()", globals())

timeit("solution_3()", globals())

timeit("solution_4()", globals())

# timeit("solution_5()", globals())

print()

timeit("solution_3_bis()", globals())

print(type(solution_3()))

print(type(solution_3_bis()))