PS1.md

Implementation & Simulation Problems

These problems test your ability to translate a problem's rules directly into code.

• Team (231A)
  Rating: 800
  Topic: Simple Loop

  Hint

  For each problem, sum the three inputs (0s and 1s). If the sum is 2 or greater, add 1 to your answer.

• Stones on the Table (266A)
  Rating: 800
  Topic: String Iteration

  Hint

  Iterate through the string from the first to the second-to-last character. Compare each character `s[i]` with the next one `s[i+1]`. If they're the same, increment a counter.

• Queue at the School (266B)
  Rating: 900
  Topic: Array Simulation

  Hint

  You need to simulate the process `t` times. In each second, iterate through the queue and find all adjacent "BG" pairs to swap. Be careful not to swap a newly moved 'B' again in the same second.

• Nearly Lucky Number (110A)
  Rating: 800
  Topic: Digit Manipulation

  Hint

  First, count the number of '4's and '7's in the input number. Let this count be `c`. Then, check if `c` itself is a lucky number (i.e., 4 or 7).

• Two-gram (977B)
  Rating: 900
  Topic: Substring Counting

  Hint

  Iterate through all substrings of length 2. Use a map or dictionary to store the frequency of each two-gram. Then, find the one with the highest count.