day14.py

rxns = '''1 GZJM, 2 CQFGM, 20 SNPQ, 7 RVQG, 3 FBTV, 27 SQLH, 10 HFGCF, 3 ZQCH => 3 SZCN
4 FCDL, 6 NVPW, 21 GZJM, 1 FBTV, 1 NLSNB, 7 HFGCF, 3 SNPQ => 1 LRPK
15 FVHTD, 2 HBGFL => 4 BCVLZ
4 GFGS => 4 RVQG
5 BCVLZ, 4 LBQV => 7 TWSRV
6 DWKTF, 4 VCKL => 4 KDJV
16 WZJB => 4 RBGJQ
8 RBGJQ, 5 FCDL, 2 LWBQ => 1 MWSX
100 ORE => 7 WBRL
7 PGZGQ => 5 FVHTD
1 JCDML, 2 TWSRV => 9 JSQSB
3 WZJB, 1 NXNR => 6 XFPVS
7 JPCPK => 8 JCDML
11 LWBQ, 8 XFPVS => 9 PSPFR
2 TWSRV => 8 NVPW
2 LBQV => 1 PMJFD
2 LCZBD => 3 FBTV
1 WBQC, 1 ZPNKQ => 8 JPCPK
44 HFGCF, 41 PSPFR, 26 LMSCR, 14 MLMDC, 6 BWTHK, 3 PRKPC, 13 LRPK, 50 MWSX, 8 SZCN => 1 FUEL
1 XFPVS => 4 BJRSZ
1 GWBDR, 1 MBQC => 4 HZPRB
2 BJRSZ, 9 KDJV, 1 XFPVS => 8 SNVL
7 PMJFD, 30 SNVL, 1 BJRSZ => 2 JMTG
8 SNVL, 1 RBGJQ => 9 FCDL
2 HZPRB => 6 NLSNB
2 GRDG => 9 VCKL
1 FVHTD => 9 WZJB
130 ORE => 2 GRDG
3 WZJB, 1 GFGS, 1 NXNR => 9 SNPQ
9 VCKL => 5 WBQC
1 WBRL, 11 FPMPB => 7 PGZGQ
118 ORE => 3 LMSCR
3 SQLH, 1 PMJFD, 4 XJBL => 7 MLMDC
1 LMSCR, 10 GRDG => 2 TBDH
6 DWKTF => 2 SQLH
2 BJRSZ, 1 PGZGQ, 3 NXNR => 7 MBQC
5 PRKPC => 7 NXNR
9 SQLH => 5 LCZBD
1 FCDL => 9 CQFGM
5 PGZGQ, 1 TBDH => 8 HBGFL
15 JSQSB => 5 HFGCF
2 PGZGQ, 1 VCKL => 4 ZPNKQ
3 FBTV, 3 JMTG => 5 QLHKT
1 ZGZST, 2 LCZBD => 7 GFGS
2 RVQG => 4 ZQCH
1 ZPNKQ => 5 LBQV
3 LWBQ => 8 XJBL
1 LBQV, 9 JCDML => 3 GWBDR
8 VCKL, 6 FVHTD => 9 DWKTF
3 JCDML => 3 ZGZST
160 ORE => 5 FPMPB
3 SQLH, 22 LBQV, 5 BCVLZ => 6 PRKPC
1 WZJB => 2 GZJM
10 ZGZST => 2 LWBQ
5 TBDH, 19 NXNR, 9 QLHKT, 2 KDJV, 1 SQLH, 1 GWBDR, 6 HFGCF => 4 BWTHK'''

from math import ceil
from copy import deepcopy

class chemEq:
    def __init__(self, strBal):
        ingredients, results = strBal.split(' => ')
        amt, self.result = results.split()
        self.resAmt = int(amt)
        self.ingredients = {}
        for i in ingredients.split(', '):
            amt, ing = i.split(' ')
            self.ingredients[ing] = int(amt)
    def __mul__(self,amt):
        ingredients = self.ingredients.copy()
        for k in ingredients.keys():
            ingredients[k] *= amt
        ingredients[self.result] = self.resAmt*amt
        return ingredients
    def scale(self,amt):
        self.resAmt *= amt
        for k in self.ingredients.keys():
            self.ingredients[k] *= amt
    def replaceWithIngredients(self,recipes):
        newIngredients = {}
        for k,v in self.ingredients.items():
            if not k == 'ORE' and v > 0:
                #print ('need', v, k)
                recipe = recipes[k]
                recipe = recipe * ceil(v/recipe.resAmt)
                self.ingredients[k] -= recipe[k]
                #print ('made', recipe[k])
                del recipe[k]
                for ky,vl in recipe.items():
                    #print ('by using:',vl,ky)
                    if ky in self.ingredients:
                        self.ingredients[ky] += vl
                    elif ky in newIngredients:
                        newIngredients[ky] += vl
                    else:
                        newIngredients[ky] = vl
        self.ingredients.update(newIngredients)
        
reactions = [r for r in rxns.split('\n')]
eqns = [chemEq(rxn) for rxn in reactions]
recipes = {r.result:r for r in eqns}
fuel = recipes['FUEL']
for _ in range(10):
    fuel.replaceWithIngredients(recipes)
print (fuel.ingredients['ORE'] )

reactions = [r for r in rxns.split('\n')]
eqns = [chemEq(rxn) for rxn in reactions]
recipes = {r.result:r for r in eqns}
fuel = recipes['FUEL']
print ('initial guess >',1e12/168046)
fuel2 = deepcopy(fuel)
# manually iterated until correct scale (FUEL) found
# not pretty, but it only took a couple minutes
fuel2.scale(6972986)
for _ in range(10):
    fuel2.replaceWithIngredients(recipes)
print (fuel2.ingredients['ORE'] )