题解 | 无法吃午餐的学生数量

class Solution:
    def countStudents(self , students: List[int], sandwiches: List[int]) -> int:
        i = 0 # 栈顶三明治不满足的学生数量
        while i < len(students): 
            if students[0] == sandwiches[0]:
                students.pop(0)
                sandwiches.pop(0)
                i = 0 # 三明治和学生匹配上了，换下一个三明治，数值重置
            else:
                students.append(students.pop(0))
                i += 1 # 未匹配上，则无法拿到三明治的学生数量+1
        return len(students)