29 lines
1.2 KiB
Python
29 lines
1.2 KiB
Python
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def checkio(expression):
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OPENING_BRACKETS = ["(", "[", "{"]
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CLOSING_BRACKETS = [")", "]", "}"]
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current_bracket = []
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for letter in expression:
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if letter in CLOSING_BRACKETS:
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if len(current_bracket) == 0:
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return False
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else:
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last_bracket = current_bracket[-1:][0]
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if OPENING_BRACKETS.index(last_bracket) == CLOSING_BRACKETS.index(letter):
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current_bracket.pop()
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else:
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return False
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if letter in OPENING_BRACKETS:
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current_bracket.append(letter)
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return len(current_bracket) == 0
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# These "asserts" using only for self-checking and not necessary for auto-testing
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if __name__ == '__main__':
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assert checkio("((5+3)*2+1)") == True, "Simple"
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assert checkio("{[(3+1)+2]+}") == True, "Different types"
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assert checkio("(3+{1-1)}") == False, ") is alone inside {}"
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assert checkio("[1+1]+(2*2)-{3/3}") == True, "Different operators"
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assert checkio("(({[(((1)-2)+3)-3]/3}-3)") == False, "One is redundant"
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assert checkio("2+3") == True, "No brackets, no problem"
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assert checkio("(((([[[{{{3}}}]]]]))))") == False, "No brackets, no problem"
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