>>808
#include <stdio.h>
int main()
{
double a1,a2,a3,a4;

a1=1+1/2;
a2=1+1.0/2;
a3=1+1/2.0;
a4=1.0+1.0/2.0;

printf("a1=%lf a2=%lf a3=%lf a4=%lf \n", a1, a2, a3, a4);
return 0;
}