class Solution(object):def recursive(self,formula):left = right = Nonefor i,v in enumerate(formula):if v == '(':left = ielif v == ')':right = ibreakif left == None and right == None:return formulalf = formula[:left]parse = formula[left+1:right]times = ''for i in range(right+1,len(formula)):if formula[i].isdigit():times += formula[i]else:if i != len(formula) - 1:i -= 1breakif times != '':times = int(times)rf = formula[i+1:]if times == '':ts = parseelse:parseList = []val = ''val_num = ''parse += '#'for i in parse:#print parseListif i.islower():val += i#parseList.append(val)elif i.isupper():if val != '':parseList.append(val)if val_num != '':parseList.append(str(int(val_num) * int(times)))val_num = ''elif val_num == '' and val != '':parseList.append(str(times))val = ielif i.isdigit():if val != '':parseList.append(val)val = ''val_num += ielif i == '#':if val != '':parseList.append(val)if val_num != '':parseList.append(str(int(val_num) * int(times)))elif val_num == '' and val != '':parseList.append(str(times))ts = ''.join(parseList)return self.recursive(lf + ts + rf)def countOfAtoms(self, formula):""":type formula: str:rtype: str"""f =  self.recursive(formula)i = 1#print f#transform MgO2H2 -> Mg1O2H2while i < len(f):if f[i].isupper() and f[i-1].isdigit() == False:f = f[:i] + '1' + f[i:]i = 1i += 1if f[-1].isdigit() == False:f += '1'dic = {}key = ''val = ''# H11He49N1O35B7N46Li20for i in f:if i.isdigit():val += ielse:if val == '':key += ielse:if key not in dic:dic[key] = int(val)else:dic[key] += int(val)key = ival = ''if key not in dic:dic[key] = int(val)else:dic[key] += int(val)keys = dic.keys()keys.sort()res = ''#print dicfor i in keys:res += iif dic[i] > 1:res += str(dic[i])return res