leetcode_0150.py

class Solution:
    def evalRPN(self, tokens: list[str]) -> int:
        stack: list = []

        for char in tokens:
            if char in "+-*/":
                val2, val1 = stack.pop(), stack.pop()
                if char == "+":
                    val1 += val2
                elif char == "-":
                    val1 -= val2
                elif char == "*":
                    val1 *= val2
                else:
                    val1 /= val2
                stack.append(int(val1))

            else:
                stack.append(int(char))

        return int(stack[-1])


s = Solution()
print(s.evalRPN(["4","13","5","/","+"]))
print(s.evalRPN(["10", "6", "9", "3", "+", "-11", "*", "/", "*", "17", "+", "5", "+"]))
print(s.evalRPN(["-78","-33","196","+","-19","-","115","+","-","-99","/","-18","8","*","-86","-","-","16","/","26","-14","-","-","47","-","101","-","163","*","143","-","0","-","171","+","120","*","-60","+","156","/","173","/","-24","11","+","21","/","*","44","*","180","70","-40","-","*","86","132","-84","+","*","-","38","/","/","21","28","/","+","83","/","-31","156","-","+","28","/","95","-","120","+","8","*","90","-","-94","*","-73","/","-62","/","93","*","196","-","-59","+","187","-","143","/","-79","-89","+","-"]))