cosmetics

joblocks.py

#!/usr/bin/env python3
import os
import sys
import time
from itertools import *
import pprint; pp = pprint.pprint

def inclusive_range(smallest, largest, step):
	N = 1 + int(round((largest - smallest) / step))
	return [smallest + k*step for k in range(N)]

decimals = 4
factor = 10**decimals

blocks = []
blocks += inclusive_range(.1001, .1009, .0001)
blocks += inclusive_range(.101,  .149,  .001)
blocks += inclusive_range(.050,  .950,  .050)
blocks += [1,2,3,4]
blocks = [int(round(v*factor)) for v in blocks] # don't wanna calculate with floats
blocks.sort(reverse=True) # better time, moves most additions to the end

# collect sum lengths and shortest combinations
# this will contain the combination of NO blocks, nicer to deal with
solutions = {0: ()} # {sum: list}

ta = time.perf_counter()
for i,block in enumerate(blocks):
	# add this block to previous solutions
	t0 = time.perf_counter()

	updates = {
		(Sum + block): List + (block,)
		for Sum,List in solutions.items()
		if Sum+block not in solutions
		or len(List)+1 < len(solutions[Sum+block])
	}
	solutions.update(updates)

	t1 = time.perf_counter()

	print(f"{i+1}: {block/factor:.{decimals}f} -> {len(solutions)} combinations, {t1-t0:.3f}s")

tb = time.perf_counter()

print(f"time: {tb-ta:.3f}s")
print("shortest sums:", sorted(solutions.keys())[:5]) # [0, 500, 1000, 1001, 1002]
print("longest sums:", sorted(solutions.keys())[-5:]) # [264293, 264294, 264295, 264795, 265295]

# example
print("3.9762 =", solutions[39762]) # (1002, 1260, 7500, 30000)