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

Examples:

```
Input: "69"
Output: true
Input: "962"
Output: false
```

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

Examples:

```
Input: "69"
Output: true
Input: "962"
Output: false
```

This is a ridiculous question, but here is a solution that beats 100% of the OJ.

```
class Solution {
public boolean isStrobogrammatic(String num) {
Set<String> set = new HashSet<>(Arrays.asList("00","11", "69", "96", "88", "696"));
for(int i=0, j = num.length()-1;i<=j;i++, j--){
if(!set.contains(num.charAt(i)+""+num.charAt(j))) return false;
}
return true;
}
}
```