Baseball Game

Baseball Game.py

class Solution:
    def calPoints(self, ops):
        """
        :type ops: List[str]
        :rtype: int
        """
        n = len(ops)
        keyStack = [0 for i in range(n)]
        
        for i in range(n):
            if ops[i] == "+":
                r1 = keyStack[len(keyStack) -1]
                r2 = keyStack[len(keyStack) -2]
                keyStack.append(r1+r2)
            elif ops[i] == "D":
                r1 = keyStack[len(keyStack) -1]
                keyStack.append(r1 * 2)
            elif ops[i] == "C":
                keyStack = keyStack[:len(keyStack)-1]
            else:
                keyStack.append(int(ops[i]))
           
        
        return sum(keyStack)