# [Solved] An integer x is a good if after rotating each digit individually by 180 degrees, we get a valid number that is different from x. Each digit must be rotated – we cannot choose to leave it alone. ## Question

An integer `x` is a good if after rotating each digit individually by 180 degrees, we get a valid number that is different from `x`. Each digit must be rotated – we cannot choose to leave it alone.

A number is valid if each digit remains a digit after rotation. For example:

• `0``1`, and `8` rotate to themselves,
• `2` and `5` rotate to each other (in this case they are rotated in a different direction, in other words, `2` or `5` gets mirrored),
• `6` and `9` rotate to each other, and
• the rest of the numbers do not rotate to any other number and become invalid.

Given an integer `n`, return the number of good integers in the range `[1, n]`.

Example 1:

```Input: n = 10
Output: 4
Explanation: There are four good numbers in the range [1, 10] : 2, 5, 6, 9.
Note that 1 and 10 are not good numbers, since they remain unchanged after rotating.
```

Example 2:

```Input: n = 1
Output: 0
```

Example 3:

```Input: n = 2
Output: 1
```

Constraints:

• `1 <= n <= 104`

## Python Solution

```class Solution:
def rotatedDigits(self, N: int) -> int:
d = {'0':'0' , '1':'1' , '2':'5' , '8':'8' , '5':'2' , '6':'9' , '9':'6' }
def checker(n):
k=''
for i in str(n):
if i not in d.keys():
return False
else:
k+=d[i]
if k!=str(n):
return True
else:
return False
l=0
for i in range(N+1):
if checker(i):
l+=1
return l```