[LeetCode] 150. Evaluate Reverse Polish Notation

轉自LeetCode

Evaluate the value of an arithmetic expression in Reverse Polish Notation.

Valid operators are +, -, *, /. Each operand may be an integer or another expression.

Some examples:

  ["2", "1", "+", "3", "*"] -> ((2 + 1) * 3) -> 9
  ["4", "13", "5", "/", "+"] -> (4 + (13 / 5)) -> 6

<Solution>
直覺用 stack 來解，想法如下

• 如果是數字，就轉乘 int 放到 stack

• 如果是運算符號，就把最上面兩個數字拿出來做運算，結果再放到 stack

code如下
c++

kotlin