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) {
        int count = 0;
        while(students.size() && count < students.size())
        {
            if( students[0] == sandwiches[0])
            {
                students.erase(students.begin());
                sandwiches.erase(sandwiches.begin());
                count = 0;
            }
            else 
            {
                int val = students[0];
                students.erase(students.begin());
                students.push_back(val);
                ++count;
            }
        }

        return students.size();
    }
};