Hey everyone, Today we will solve Find the Student that Will Replace the Chalk - Leet Code 1894 in three simple steps.

• Calculate the total chalk needed for one full round

• Reduce k modulo total_chalk

• Iterate through the array to find the first student who can't complete their turn

 def chalkReplacer(self, chalk: List[int], k: int) -> int:
        # Step 1: Calculate the total chalk needed for one full round
        total_chalk = sum(chalk)
        # Step 2: Reduce k modulo total_chalk
        k %= total_chalk

        # iterate though array who can't find their turn 
        for i in range(len(chalk)):
            if k < chalk[i]:
                return i

            # decrement k by chalk[i]

            k-=chalk[i]

Complexity

• Time complexity:
  O(n), where n is the number of students.

• Space complexity: O(1)

Video Explanation