confusing-number

< Previous 　　　　　　　　　　　　　　　　 Next >

1056. Confusing Number (Easy)

Given a number N, return true if and only if it is a confusing number, which satisfies the following condition:

We can rotate digits by 180 degrees to form new digits. When 0, 1, 6, 8, 9 are rotated 180 degrees, they become 0, 1, 9, 8, 6 respectively. When 2, 3, 4, 5 and 7 are rotated 180 degrees, they become invalid. A confusing number is a number that when rotated 180 degrees becomes a different number with each digit valid.

 

Example 1:

Input: 6
Output: true
Explanation: 
We get 9 after rotating 6, 9 is a valid number and 9!=6.

Example 2:

Input: 89
Output: true
Explanation: 
We get 68 after rotating 89, 86 is a valid number and 86!=89.

Example 3:

Input: 11
Output: false
Explanation: 
We get 11 after rotating 11, 11 is a valid number but the value remains the same, thus 11 is not a confusing number.

Example 4:

Input: 25
Output: false
Explanation: 
We get an invalid number after rotating 25.

 

Note:

1. 0 <= N <= 10^9
2. After the rotation we can ignore leading zeros, for example if after rotation we have 0008 then this number is considered as just 8.

Related Topics

[Math]

Similar Questions

1. Strobogrammatic Number (Easy)
2. Confusing Number II (Hard)

Hints

Hint 1

Reverse each digit with their corresponding new digit if an invalid digit is found the return -1. After reversing the digits just compare the reversed number with the original number.