Is the phone number valid?
Phone numbers in the United States typically consist of 11 digits:
- 1-digit country code
- 3-digit area code
- 3-digit central office or exchange code
- 4-digit subscriber number
A valid example can be:
+1 (555) 555-1234. So, the phone number should start with a
+1, followed by a space and then 3 digits enclosed in parentheses. The last 7 digits are separated by a hyphen after the 3 digits.Given a phone number print,
The phone is valid if the phone is valid, and Invalid number otherwise.Input | Output |
+1 (555) 555-1234 | The phone is valid |
+1 (5a5) 555-1234 | Invalid number |
+1 (55) 555-1234 | Invalid number |
Constraints
Time limit: 2 seconds
Memory limit: 512 MB
Output limit: 1 MB