N名学生的数据已在主函数中放入结构体数组S中，请编写函数fun，它的功能是：把分数最低的学生数据放在b所指的数组中，注意：分数最低的学生可能不止一个，函数返回分数最低的人数。-N student data has been placed in the main function of the array of structures S, write a function fun, its function is to: the lowest score of student data on the array b referred to in Note: The minimum score students may more than one, the function returns the number of the lowest scores.