题解 | 无法吃午餐的学生数量

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param students int整型vector 
     * @param sandwiches int整型vector 
     * @return int整型
     */
    int countStudents(vector<int>& students, vector<int>& sandwiches) {
        // write code here
        queue<int> student_queue;
        queue<int> sandwiches_queue;
        for (int s : students) student_queue.push(s);
        for (int s : sandwiches) sandwiches_queue.push(s);
        int mark=0;
        while(!student_queue.empty()&&!sandwiches_queue.empty())
        {
            if(student_queue.front()==sandwiches_queue.front())
            {
                student_queue.pop();
                sandwiches_queue.pop();
                mark=0;
            }
            else
            {
                student_queue.push(student_queue.front());
                student_queue.pop();
                mark++;
            }
            if(mark==student_queue.size())
            {
                break;
            }
        }
        return student_queue.size();
    }
};