✨ 문제
Number of Students Unable to Eat Lunch
The school cafeteria offers circular and square sandwiches at lunch break, referred to by numbers 0 and 1 respectively. All students stand in a queue. Each student either prefers square or circular sandwiches.
The number of sandwiches in the cafeteria is equal to the number of students. The sandwiches are placed in a stack. At each step:
- If the student at the front of the queue prefers the sandwich on the top of the stack, they will take it and leave the queue.
- Otherwise, they will leave it and go to the queue's end.
This continues until none of the queue students want to take the top sandwich and are thus unable to eat.
You are given two integer arrays students and sandwiches where sandwiches[i] is the type of the ith sandwich in the stack (i = 0 is the top of the stack) and students[j] is the preference of the jth student in the initial queue (j = 0 is the front of the queue). Return the number of students that are unable to eat.
https://leetcode.com/problems/number-of-students-unable-to-eat-lunch/description/
✨ 최종코드
class Solution {
public int countStudents(int[] students, int[] sandwiches) {
Queue<Integer> studentQueue = new LinkedList<>();
for (int student : students) {
studentQueue.add(student);
}
int index = 0; // sandwiches 배열의 인덱스
int unableToEatCount = 0; // 먹을 수 없는 학생 수
while (!studentQueue.isEmpty() && unableToEatCount < studentQueue.size()) {
if (studentQueue.peek() == sandwiches[index]) {
studentQueue.poll(); // 학생이 샌드위치를 가져가고 줄에서 나감
index++; // 다음 샌드위치로 이동
unableToEatCount = 0; // 초기화
} else {
studentQueue.add(studentQueue.poll()); // 줄 맨 뒤로 이동
unableToEatCount++; // 먹을 수 없는 학생 수 증가
}
}
return studentQueue.size();
}
}