--- Day 4: Secure Container ---
You arrive at the Venus fuel depot only to discover it's protected by a password. The Elves had written the password on a sticky note, but someone threw it out.
However, they do remember a few key facts about the password:
- It is a six-digit number.
- The value is within the range given in your puzzle input.
- Two adjacent digits are the same (like
- Going from left to right, the digits never decrease; they only ever increase or stay the same (like
Other than the range rule, the following are true:
111111meets these criteria (double
11, never decreases).
223450does not meet these criteria (decreasing pair of digits
123789does not meet these criteria (no double).
How many different passwords within the range given in your puzzle input meet these criteria?