## Description

https://leetcode.com/problems/strobogrammatic-number/

A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).

Write a function to determine if a number is strobogrammatic. The number is represented as a string.

**Example 1:**

Input:num = "69"Output:true

**Example 2:**

Input:num = "88"Output:true

**Example 3:**

Input:num = "962"Output:false

**Example 4:**

Input:num = "1"Output:true

## Explanation

Create a reference mapping for strobo grammatic numbers. Then use the two-pointer technique to check if the numbers from left and right match the mapping.

## Python Solution

```
class Solution:
def isStrobogrammatic(self, num: str) -> bool:
mapping = {"9": "6", "6": "9", "8": "8", "1": "1", "0": "0"}
left = 0
right = len(num) - 1
while left <= right:
if num[left] in mapping and mapping[num[left]] == num[right]:
left += 1
right -= 1
else:
return False
return True
```

- Time Complexity: ~N
- Space Complexity: ~1