Characters of strings can be accessed with
brackets and the indexing starts with 0.
To access the last character of a string
s, we can write
s[len(s) - 1]. This might become messy with larger expressions and luckily there is a more concise way of accessing characters from the end through negative indexing:
# 01234 => 5 characters greeting = 'hello' print(greeting[len(greeting) - 1]) # o print(greeting[len(greeting) - 2]) # l print(greeting[len(greeting) - 3]) # l
# 01234 greeting = 'hello' print(greeting[-1]) # o print(greeting[-2]) # l print(greeting[-3]) # l
Both of these programs are equivalent but the second one is more concise and easier to read.
You are working in the security department and they ask you to add another check for user passwords. The passwords are considered secure if the first
3letters together are not equal to the last
3letters (in reverse order).
The input contains a single line - the password.
The program should print
secureif the password is considered secure, and
Time limit: 1 seconds
Memory limit: 512 MB
Output limit: 1 MB