从图 1 所示的文件 fin.txt 中读取学生姓名、身高和体重，计算并显示它们的平均值，并且将显示结果保存到文件 fout.txt 中。

图 1：输入输出文件示例

C语言代码清单 1：读取学生姓名、身高和体重，计算并显示它们的平均值

#include

#include

int main( )

{

int num = 0;

FILE *fp1,*fp2;

char name[100];

double height,weight,hSum=0.0,wSum=0.0;

if((fp1 = fopen("fin.txt","r")) == NULL)

printf("\a文件fin.txt打开失败！\n");

else{

fp2 = fopen("fout.txt","w");

while(fscanf(fp1,"%s%lf%lf",name,&height,&weight) == 3){

printf("%-10s %5.1f %5.1f\n",name,height,weight);

fprintf(fp2,"%-10s %5.1f %5.1f\n",name,height,weight);

num++;

hSum += height;

wSum += weight;

}

printf("----------------------\n");

printf("平均 %5.1f %5.1f\n",hSum/num,wSum/num);

fprintf(fp2,"----------------------\n");

fprintf(fp2,"平均 %5.1f %5.1f\n",hSum/num,wSum/num);

fclose(fp1); fclose(fp2);

}

system("pause");

return 0;

}

运行结果为：

Linda      155.0  40.5

Mary       157.0  39.5

Tony       150.0  38.3

Sala       158.0  42.8

———————-

平均       155.0  40.3