class Solution:
def evalRPN(self, tokens: List[str]) -> int:
surya = []
x = 0
y = 0
res = 0
for i in range(len(tokens)):
if tokens[i].isnumeric():
surya.append(int(tokens[i]))
else:
y = surya.pop()
x = surya.pop()
if(tokens[i] == "*"):
res = x*y
elif(tokens[i] == "/"):
res = x/y
elif(tokens[i] == "+"):
res = x+y
else:
res = x-y
return res
输入:记号=["2","1","+","3","*"]输出:9
我的输出:
IndexError:从空列表弹出
x = surya.pop()
Line 14 in evalRPN (Solution.py)
ret = Solution().evalRPN(param_1)
Line 43 in _driver (Solution.py)
_driver()
Line 54 in <module> (Solution.py)
输出如上图所示,代码看起来不错,但不起作用。。。这是一个问题从leet代码链接到问题的图像是附加
当您处理一个运算时,您应该将结果放在surya
上,否则当您找到下一个运算符时,您将只有一个操作数要处理。顺便说一句,这也意味着你不需要res
变量,最终结果将是surya
中唯一剩下的值