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| 1 | +# Basic Calculator III |
| 2 | +# https://leetcode.com/problems/basic-calculator-iii/ |
| 3 | + |
| 4 | +class Calculator(object): |
| 5 | + def __init__(self): |
| 6 | + self.operators = ['+', '-', '*', '/'] |
| 7 | + |
| 8 | + def addition(self, a, b): |
| 9 | + return a+b |
| 10 | + |
| 11 | + def subtraction(self, a, b): |
| 12 | + return a-b |
| 13 | + |
| 14 | + def multiplacation(self, a, b): |
| 15 | + return a*b |
| 16 | + |
| 17 | + def division(self, a, b): |
| 18 | + if (a == 0 or b == 0): |
| 19 | + return 0 |
| 20 | + return a/(b) |
| 21 | + |
| 22 | + def operation(self, a, b, operator): |
| 23 | + expressions = { |
| 24 | + '+': self.addition(a, b), |
| 25 | + '-': self.subtraction(a, b), |
| 26 | + '*': self.multiplacation(a, b), |
| 27 | + '/': self.division(a, b) |
| 28 | + } |
| 29 | + return expressions[operator] |
| 30 | + |
| 31 | + def precedence(self, operator): |
| 32 | + precidence = { |
| 33 | + '*':1, |
| 34 | + '/':1, |
| 35 | + '+':0, |
| 36 | + '-':0, |
| 37 | + } |
| 38 | + return precidence[operator] |
| 39 | + |
| 40 | + |
| 41 | +class Solution(object): |
| 42 | + |
| 43 | + def convertInToList(self, s): |
| 44 | + newList = [] |
| 45 | + number = "" |
| 46 | + for char in list(s): |
| 47 | + if char.isnumeric(): |
| 48 | + number = number + char |
| 49 | + else: |
| 50 | + if (number != ""): |
| 51 | + newList.append(int(number)) |
| 52 | + number = "" |
| 53 | + newList.append(char) |
| 54 | + return newList |
| 55 | + |
| 56 | + def calculate(self, s): |
| 57 | + s = s+')' |
| 58 | + s = self.convertInToList(s) |
| 59 | + numStack = [] |
| 60 | + operatorStack = ['('] |
| 61 | + calculator = Calculator() |
| 62 | + for char in s: |
| 63 | + print numStack, operatorStack |
| 64 | + if(char == '('): |
| 65 | + operatorStack.append(char) |
| 66 | + elif(char == ')'): |
| 67 | + while(operatorStack and operatorStack[-1] != '('): |
| 68 | + n2 = numStack.pop() |
| 69 | + n1 = numStack.pop() |
| 70 | + op = operatorStack.pop() |
| 71 | + print "number1", n1, "number2", n2, "operator", op |
| 72 | + ans = calculator.operation(n1, n2, op) |
| 73 | + numStack.append(ans) |
| 74 | + # pop "(" |
| 75 | + if operatorStack: |
| 76 | + operatorStack.pop() |
| 77 | + elif(char in calculator.operators): |
| 78 | + operatorStack.append(char) |
| 79 | + else: |
| 80 | + ans = char |
| 81 | + while(operatorStack and operatorStack[-1] == '*' or operatorStack[-1] == '/'): |
| 82 | + op = operatorStack.pop() |
| 83 | + num = numStack.pop() |
| 84 | + print "current num", ans, "top of stack", num, "operator", op, |
| 85 | + ans = calculator.operation(num, ans, op) |
| 86 | + print "answer", ans |
| 87 | + numStack.append(ans) |
| 88 | + return int(numStack[-1]) |
| 89 | + """ |
| 90 | + :type s: str |
| 91 | + :rtype: int |
| 92 | + """ |
| 93 | + |
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