编辑代码

/*
#include <stdio.h>
void main(){
    printf("Hello world\n");
}
*/

/*
#include <stdio.h>
#include<math.h>

int main()
{
double a,b;
printf("input number : \n");
scanf("%lf",&a);
b=sin(a);
printf("sine of %lf is %lf",a,b);
return 0;
}
*/

/*
#include <stdio.h>
#include<math.h>
void main(){
    double a,b;
    printf("Hello world\n");
    scanf("%lf",&a);
    b=cos(a);
    printf("this is %lf is %lf",a,b);
    
}
*/

#include<stdio.h>
#define PRICE 30
int main()
{
    int num,total;
    num=10;
    total=num*PRICE;
    printf("total=%d",total);
    return 0;
}