Advent of Code 2020: Python Solution Day 14

with open("day14.txt", 'r') as fp: lines = [line.rstrip() for line in fp.readlines()] memory = {} masks = [] curr_mask = None curr_value = None curr_address = None for line in lines: k, v = line.split(" = ") if k == "mask": masks.append(v) curr_mask = v else: # get address  curr_address = int(k[4:-1]) curr_value = int(v) bin_value = list(bin(curr_value)[2:].zfill(36)) new_value = [0] * 36 for i, (mask, value) in enumerate(zip(curr_mask, bin_value)): # do nothing if X  if mask == "X": new_value[i] = value else: # change value to mask else  new_value[i] = mask memory[curr_address] = int("".join(new_value), 2) print(f"Part one solution: {sum(memory.values())}") 

""" If the bitmask bit is 0, the corresponding memory address bit is unchanged. If the bitmask bit is 1, the corresponding memory address bit is overwritten with 1. If the bitmask bit is X, the corresponding memory address bit is floating. """ with open("day14.txt", 'r') as fp: lines = [line.rstrip() for line in fp.readlines()] memory = {} for line in lines: k, v = line.split(" = ") if k == "mask": masks.append(v) curr_mask = v else: # get address  curr_address = int(k[4:-1]) curr_value = int(v) bin_add = list(bin(curr_address)[2:].zfill(36)) new_add = ["0"] * 36 v = len(list(bin(curr_address)[2:])) for i, (mask, value) in enumerate(zip(curr_mask, bin_add)): # if mask bit is floating then keep it floating on new address too  if mask == "X": new_add[i] = "X" elif mask == "0": # change value to mask else  new_add[i] = value elif mask == "1": new_add[i] = "1" new_add = "".join(new_add) # count floatings  num_poss = new_add.count("X") flucts = [] for i in range(2**num_poss): flucts.append( list(bin(i)[2:].zfill(num_poss))) for fluct in flucts: i = 0 nadd = "" for a in new_add: if a == "X": nadd+=str(fluct[i]) i+=1 else: nadd+=str(a) memory[int(nadd, 2)]=curr_value sum(memory.values())