为什么数字后会自动加小数，且float double 都是六个零
#include <stdio.h>
int main()
{
char c = 97;
int n = c; //将c赋值给n
float f =c; //将c赋值给f
double d = c; //将c赋值给d
printf("%d\n",n);
printf("%f\n",f);
printf("%lf\n",d);
return 0;
}
