急~c语言求平均数，不知道错在哪~~结果总是出错~谢谢了~

Question

#include<stdio.h>
int main(void)
{
int a,b,c;
int sum;
double average;
printf("输入三个整数: \n");
scanf("%d %d %d", &a, &b,&c);

sum=a+b+c;
printf(" 和: %d \n.",sum);
average=sum/3;
printf("平均: %f \n.",average);

return 0;
}

Answer 1

变量sum是int类型的
sum/3是整除运算，所以平均值大多是错的，
average=sum/3;
这句改成：
average=sum*1.0/3;
或者改成
average=((double)sum)/3;
就行了

Answer 2

#include<stdio.h>
int main(void)
{
int a,b,c;
int sum=0;
float average;
printf("输入三个整数: \n");
scanf("%d %d %d", &a, &b,&c);

sum=a+b+c;
printf(" 和: %d \n",sum);
average=sum/3;
printf("平均: %f \n",average);

return 0;
}

Answer 3

#include<stdio.h>
int main(void)
{
int a,b,c;
int sum;
double average;
printf("输入三个整数: \n");
scanf("%d %d %d", &a, &b,&c);

sum=a+b+c;
printf(" 和: %d \n.",sum);
average=((double)sum)/3;
printf("平均: %f \n.",average);

return 0;
}

Answer 4

average=(double)sum/3