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  1. def rpn(s):
  2. 	lex=parse(s)
  3. 	s2=[]
  4. 	r=[]
  5. 	oper=["+","-","*","/","(",")"]
  6. 	for a in lex:
  7. 		if a=="(":
  8. 			s2=[a]+s2
  9. 		elif a in oper:
  10. 			if s2==[]:
  11. 				s2=[a]
  12. 			elif a==")":
  13. 				while(True):
  14. 					q=s2[0]
  15. 					s2=s2[1:]
  16. 					if q=="(":
  17. 						break
  18. 					r+=[q]
  19. 			elif prty(s2[0]) < prty(a):
  20. 				s2=[a]+s2
  21. 			else:
  22. 				while(True):
  23. 					if s2==[]:
  24. 						break
  25. 					q=s2[0]
  26. 					r+=[q]
  27. 					s2=s2[1:]
  28. 					if prty(q)==prty(a):
  29. 						break
  30. 				s2=[a]+s2
  31. 		else:
  32. 			r+=[a]
  33. 	while(s2 != []):
  34. 		q=s2[0]
  35. 		r+=[q]
  36. 		s2=s2[1:]
  37. 	return r
  38.  
  39. def prty(o):
  40. 	if o=="+" or o=="-":
  41. 		return 1
  42. 	elif o=="*" or o=="/":
  43. 		return 2
  44. 	elif o=="(":
  45. 		return 0
  46.  
  47. def parse(s):
  48. 	delims=["+","-","*","/","(",")"]
  49. 	lex=[]
  50. 	tmp=""
  51. 	for a in s:
  52. 		if a != " ":
  53. 			if a in delims:
  54. 				if tmp != "":
  55. 					lex+=[tmp]
  56. 				lex+=[a]
  57. 				tmp=""
  58. 			else:
  59. 				tmp+=a
  60. 	if tmp != "":
  61. 		lex+=[tmp]
  62. 	return lex
  63.  
  64. print(rpn("2+44*(56-12)/a-66"))
  65.  
  66.  
Success #stdin #stdout 0.02s 9224KB
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Standard input is empty
stdout
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['2', '44', '56', '12', '-', '*', 'a', '/', '+', '66', '-']
https://ideone.com/Aje2dI
Обратная Польская запись
language:
Python 3 (python  3.12)
created:
5 years ago
visibility:
public

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