python-leetcode面试题解之第150题逆波兰表达式求值-题解.zip

class Solution(object): def evalRPN(self, tokens): """ :type tokens: List[str] :rtype: int """ stack = [] for t in tokens: try: temp = int(t) stack.append(temp) except: b = stack.pop() a = stack.pop() if t == "+": a += b elif t == "-": a -= b elif t == "*": a *= b else: a = int(a * 1.0 / b) stack.append(a) return stack[-1]