Evaluate Reverse Polish Notation

Python在做除法时，全部是向下取整的，就是负数也是向下取整，而人正常的思维逻辑是绝对值向下取整，所以Python做这道题要小心除法的坑，Java不存在这个问题

class Solution(object):
    def evalRPN(self, tokens):
        """
        :type tokens: List[str]
        :rtype: int
        """
        stack = []

        for token in tokens:
            if token == '+':
                addNum = stack.pop()
                stack[-1] += addNum
            elif token == '-':
                minusNum = stack.pop()
                stack[-1] -= minusNum
            elif token == '*':
                mul = stack.pop()
                stack[-1] *= mul
            elif token == '/':
                dividend = stack.pop()
                divisor = stack.pop()
                if divisor == 0:
                    stack.append(0)
                    continue
                tmp = abs(divisor) / abs(dividend)
                tmp *= (abs(divisor) * abs(dividend) / (divisor * dividend))
                stack.append(tmp)
            else:
                stack.append(int(token))

        return stack[-1]

public class Solution {
    public int evalRPN(String[] tokens) {
        Stack<Integer> stack = new Stack();

        for (String token : tokens) {
            if (token.equals("+")) {
                int addNum = stack.pop();
                int base = stack.pop();
                stack.push(base + addNum);
            } else if (token.equals("-")) {
                int minusNum = stack.pop();
                int base = stack.pop();
                stack.push(base - minusNum);
            } else if (token.equals("*")) {
                int mul = stack.pop();
                int base = stack.pop();
                stack.push(mul * base);
            } else if (token.equals("/")) {
                int div = stack.pop();
                int base = stack.pop();
                stack.push(base / div);
            } else {
                stack.push(Integer.parseInt(token));
            }
        }

        return stack.pop();
    }
}