编写函数fun：从n个学生的成绩中统计出低于平均分的学生人数 ，由函数返回值返回，平均分存放在形参 ptr_ aver所指的存储单 元中 (即平均分由参数返回) 。
// Below_average_num.cpp : 定义控制台应用程序的入口点。//
#include "stdafx.h"#include<stdio.h>#include<stdlib.h>#define NUM 8
int fun( float *s, int n, float* ptr_aver );
int _tmain(int argc, _TCHAR* argv[]){ int count=0,Num=0; float Results[NUM]={0}; float Average=0; float *P_Aver_Num=NULL; /*注意这里不初始化，容易产生野指针*/
P_Aver_Num=Results; count=fun(P_Aver_Num,Num,&Average); /*调用fun()函数*/ printf("/nBelow the average %f number of students ：%d/n",Average,count);/*【出错-备注】输出格式要与变量互相匹配*/
getchar(); return 0;}
int fun( float *s, int n, float* ptr_aver ) /*实现函数*/{ int Below_Average_num=0; float *Average=ptr_aver; float sum=0; int Num=0,count=0; float *Results = s;
fflush(stdin); printf("Please enter the number of students:"); /*读入N个学生*/ scanf("%d",&Num); printf("/nPlease enter %d students in grades: ",Num); /*读入N个学生的成绩*/ for(int i = 0 ;i < Num ; i++) { scanf("_",&Results[i]); }
printf("/nstudents in the results are as follows ：/n",Num);/*输出学生成绩数组(仅用于测试）*/ for(int i = 0 ;i < Num ; i++) { printf(" %3.4f",Results[i]); } for(int i = 0 ;i < Num ; i++) /*计算学生平均成绩*/ { sum=sum+Results[i]; } *Average=sum/Num; *ptr_aver=*Average; printf("/n%d students in the results are as follows ：%3.4f",Num,*ptr_aver);
for(int i = 0 ; i < Num ; i++) /*获取低于平均成绩的人数*/ { int _temp = *(Results+i); if( _temp < *ptr_aver ) { Below_Average_num +=1; }
} return Below_Average_num;
}
