实验五

#include <stdio.h>
#include <math.h>
int main(){
    double h,c;
    double j,s;
    double a,b;
    scanf("%lf%lf",&a,&b);
    h=a+b;
    c=a-b;
    j=a*b;
    s=a/b;
    printf("%lf
",h);
    printf("%lf
",c);
    printf("%lf
",j);
    printf("%lf
",s);
    return 0;

#include <stdio.h>
#include <math.h>
int main(){
    int a,b,m=0,n=0;
    scanf("%d",&a);
    for(b=2;b<a;b++){
        if(a%b==0)
            m=m+1;
        else if(a%b!=0)
            n=n+1;
    }
    if(m!=0){
        printf("a is not a prime
");
    }else if(n!=0){
        
        printf("a is a prime
");
    }
        
        
    return 0;

}

int max2(int a,int b)
{
    if(a>=b)
        return a;
    else
        return b;
}
int max4(int a,int b,int c,int d)
{
    int m,n;
    m=max2(a,b);
    n=max2(c,d);
    if(m>=n)
        return m;
    else
        return n;
}



#include <stdio.h>
int main()
{
    int a,b,c,d,max;
    scanf("%d%d%d%d",&a,&b,&c,&d);
    max=max4(a,b,c,d);
    printf("%d
",max);
    return 0;
}

int ad(int n)
{
if(n==1||n==0)
return 1;
return n*ad(n-1);
}
#include<stdio.h>

int main()
{
int n;
scanf("%d",&n);
printf("%d
",ad(n));
return 0;
}