实验五

#include <stdio.h>

int add(int x,int y)
{
    int c;
    c = x + y;
    return c;
}

int minus(int x,int y)
{
    int c;
    c = x - y;
    return c;
}

int multip(int x,int y)
{
    int c;
    c = x * y;
    return c;
}

int quotient(int x,int y)
{
    int c;
    c = x / y;
    return c;
}

int mod(int x,int y)
{
    int c;
    c = x % y;
    return c;
}

int main()
{
    int x,y,c;
    printf("input two date:");
    scanf("%d%d",&x,&y);

    c = add(x,y);
    printf("add :%d\n",c);
    c = minus(x,y);
    printf("add :%d\n",c);
    c = multip(x,y);
    printf("add :%d\n",c);
    c = quotient(x,y);
    printf("add :%d\n",c);
    c = mod(x,y);
    printf("add :%d\n",c);

    return 0;

}

#include <stdio.h>

int prime(int x)
{
    int i;
    for (i = 2;i<x;i++)
    {
        if(x%i==0)
        {
            return 0;
        }
        else
        {
            return 1;
        }
    }
}

int main()
{
    int x,i;
    printf("输入一个数:");
    scanf("%d",&x);

    if(prime(x)==1)
    {
        printf("这是素数\n");
    }
    if(prime(x)==0)
    {
        printf("这不是素数\n");
    }

    return 0;
}

#include <stdio.h>

int main()
{
    int max4(int a,int b,int c,int d);
    int a,b,c,d,max;
    printf("输入四个数：");
    scanf("%d%d%d%d",&a,&b,&c,&d);

    max = max4(a,b,c,d);

    printf("最大的数是:%d\n",max);

    return 0;
}


int max4(int a,int b,int c,int d)
{
    int max2(int a,int b);
    int max;

    max = max2(a,b);
    max = max2(max,c);
    max = max2(max,d);

    return max;
}

int max2(int a,int b)
{
    return(a>b?a:b);
}

#include <stdio.h>

int main()
{
    double nn(int n);
    int n,s;
    printf("输入要计算阶乘的数：");
    scanf("%d",&n);

    s = nn(n);
    printf("结果为：%ld\n",s);

    return 0;
}

double nn(int n)
{
    double s;
    if(n==0||n==1)
    {
        s = 1;
    }
    else
    {
        s = n * nn(n-1);
    }

    return s;
}