How do you solve The Number of Full Rounds You Have Played on LeetCode?

The Number of Full Rounds You Have Played (LeetCode #1904) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(1) time complexity and O(1) space complexity. Key insight: Understanding how to convert time into a single unit (minutes) simplifies calculations.

What is the time complexity of The Number of Full Rounds You Have Played?

The optimal solution for The Number of Full Rounds You Have Played runs in O(1) time and uses O(1) space. The complexity is O(1) because we are performing a constant number of operations regardless of the input size.

What is the brute force solution for The Number of Full Rounds You Have Played?

The brute force approach for The Number of Full Rounds You Have Played is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute force approach checks each 15-minute interval from loginTime to logoutTime to see if it falls within the playing time. This method is straightforward but inefficient for larger time ranges. The optimal Optimal Solution approach improves this to O(1).

What algorithm or data structure is used to solve The Number of Full Rounds You Have Played?

The Number of Full Rounds You Have Played uses the following concepts: Math, String. The recommended patterns to study are: Mathematical calculations with time intervals, Handling edge cases with time formats.

What are the interview tips for The Number of Full Rounds You Have Played?

Always clarify the input format and edge cases with the interviewer. Explain your thought process as you work through the problem. Consider both brute force and optimal solutions to show your understanding.

What are common mistakes when solving The Number of Full Rounds You Have Played?

Forgetting to adjust logout time when it is earlier than login time. Counting partial rounds instead of full rounds.

#1904

The Number of Full Rounds You Have Played

Medium

MathStringMathematical calculations with time intervalsHandling edge cases with time formats

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(1)
Space	O(1)	O(1)

💡

Intuition

Time O(1)Space O(1)

The optimal solution calculates the total number of rounds directly by leveraging the properties of time intervals, which allows us to avoid iterating through each minute.

⚙️

Algorithm

4 steps

1Step 1: Convert loginTime and logoutTime into minutes since midnight.
2Step 2: If logoutTime is earlier than loginTime, adjust logoutTime to account for crossing midnight.
3Step 3: Calculate the number of full rounds before loginTime and after logoutTime.
4Step 4: Calculate the total number of rounds played by subtracting the two counts.

solution.py21 lines

1# Full working Python code
2
3def countFullRounds(loginTime, logoutTime):
4    def timeToMinutes(t):
5        h, m = map(int, t.split(':'))
6        return h * 60 + m
7
8    login = timeToMinutes(loginTime)
9    logout = timeToMinutes(logoutTime)
10
11    if logout < login:
12        logout += 24 * 60  # Adjust for crossing midnight
13
14    # Calculate full rounds
15    roundsBeforeLogin = (login // 15)
16    roundsAfterLogout = (logout // 15)
17
18    return roundsAfterLogout - roundsBeforeLogin
19
20# Example usage
21print(countFullRounds('09:31', '10:14'))  # Output: 1

ℹ

Complexity note: The complexity is O(1) because we are performing a constant number of operations regardless of the input size.

1Understanding how to convert time into a single unit (minutes) simplifies calculations.
2Recognizing when to adjust for crossing midnight is crucial for accurate results.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.