读入三个双精度数,求它们的平均值并保留此平均值小数后一位数,

#include "stdio.h"
int main() {
double a,b,c;
printf("in put a:");
scanf("%lf",&a);
printf("in put b:");
scanf("%lf",&b);
printf("in put c:");
scanf("%lf",&c);
double avg=(a+b+c)/3;
avg=(double)((int)(avg*10+0.5))/10;
printf("the avg is:%gn",avg);
return 0;
}