docs(docs): add MDX documentation pages for problems 150 (Evaluate Reverse Polish Notation) and 155 (Min Stack)

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---
title: '150. Evaluate Reverse Polish Notation'
description: You are given an array of strings tokens that represents an arithmetic expression in a Reverse Polish Notation
sidebar:
label: 'Evaluate Reverse Polish Notation'
badge: 'Medium'
---
<Badge variant="accent">Stack</Badge>
### Example 1:
- Input: `tokens = ["2","1","+","3","*"]`
- Output: `9`
- Explanation: `((2 + 1`) * `3`) = `9`
### Example 2:
- Input: `tokens = ["4","13","5","/","+"]`
- Output: `6`
- Explanation: `(4 + (13 / 5`)) = `6`
### Example 3:
- Input: `tokens = ["10","6","9","3","+","-11","*","/","*","17","+","5","+"]`
- Output: `22`
- Explanation: `((10 * (6 / ((9 + 3`) * `-11`))) + `17`) + `5 = ((10 * (6 / (12 * -11`))) + `17`) + `5 = ((10 * (6 / -132`)) + `17`) + `5 = ((10 * 0`) + `17`) + `5 = (0 + 17`) + `5 = 17 + 5 = 22`
### Constraints:
- `1 <= tokens.length <= 10^4`
- `tokens[i]` is either an operator: "+", "-", "*", or "/", or an integer in the range [-200, 200].
## Solution
```py
class Solution:
def evalRPN(self, tokens: List[str]) -> int:
stack = []
operations = {
"+": lambda x, y: int(x + y),
"-": lambda x, y: int(x - y),
"*": lambda x, y: int(x * y),
"/": lambda x, y: int(x / y),
}
for c in tokens:
if c in operations:
y = stack.pop()
x = stack.pop()
calc_func = operations[c]
result = calc_func(x, y)
stack.append(result)
else:
stack.append(int(c))
return stack[0]
```