实验三

任务一

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <windows.h>
#define N 80

void print_spaces(int n);
void print_text(int line,int col,char text[]);
void print_blank_lines(int n);

int main()
{
    int line,col,i;
    char text[N] ="hi,April~";

    srand(time(0));

    for(i=1;i<=10;++i)
    {
        line=rand()%25;
        col=rand()%80;
        print_text(line,col,text);
        Sleep(1000); //zanting1000ms

    }

    return 0;

}
void print_spaces(int n)
{
    int i;

    for(i=1;i<=n;i++)
        printf("  ");

}

void print_blank_lines(int n)
{
    int i;
    for(i=1;i<=n;i++)
        printf("\n");
}

void print_text(int line,int col,char text[])
{
    print_blank_lines(line-1);
    print_spaces(col-1);
    printf("%s",text);

}

功能是生产随机雨滴打印hi,April~

任务二

#include<stdio.h>
#include<stdlib.h>
long long fac(int n);

int main()
{
    int i,n;
    printf("enter n ");
    scanf("%d",&n);
    
    for(i=1;i<=n;++i)
    printf("%d!=%lld\n",i,fac(i));

    system("pause");
    return 0;
}

long long fac(int n)

{
    static long long p=1;

    p=p*n;

    return p;

}

#include<stdio.h>
#include<stdlib.h>
int func(int,int);

int main()
{
    int k=4,m=1,p1,p2;
    p1=func(k,m);
    p2=func(k,m);
    
    printf("%d,%d\n",p1,p2);
    
    system("pause");
    return 0;
}


int func(int a,int b)
{
    static int m=0,i=2;

    i+=m+1;
    m=i+a+b;

    return m;

}

 

静态局部变量在程序执行到该对象的声明处时被首次初始化，以后的函数调用不再进行初始化

任务三

#include<stdio.h>
#include<stdlib.h>
long long func(int n);

int main()
{
    int n;
    long long f;
    while (scanf("%d",&n)!=EOF)
    {
        f=func(n);
        printf("n=%d,f=%lld\n",n,f);
    
    }    
    
    system("pause");
    return 0;
}


long long func(int a)
{
    
    if(a==1)
        return 1;
    else
       return (func(a-1)+1)*2-1; 

}

任务四

#include<stdio.h>
#include<stdlib.h>
int func(int n,int m);

int main()
{
    int n,m;
    
    while (scanf("%d%d",&n,&m)!=EOF)
    {
        printf("n=%d,m=%d,ans=%d\n",n,m,func(n,m));
    
    }    
    
    system("pause");
    return 0;
}


int func(int a,int b)
{
    
    if(b==0&&b==a)
        return 1;
    if (b>a)
        return 0;
    if(b<0)
        return 0;

    else
       return func((a-1),b)+func((a-1),(b-1)); 

}

 

任务五

#include <stdio.h>
#include <stdlib.h>
double mypow(int x,int y);

int main ()
{
    int x,y;
    double ans;

    while(scanf("%d%d",&x,&y)!=EOF){
        ans=mypow(x,y);
    printf("%d的%d次方：%g\n\n",x,y,ans);
    }
    system("pause");
    return 0;

}

double mypow(int x,int y){
    if(y==0)
        return 1;
    if (y>0)
        return x*mypow(x,y-1);
    if (y<0)
        return 1/mypow(x,-y);


}

任务六

#include <stdio.h> //好难理解，背下来吧
#include <stdlib.h>

void hanoi(int n,char from,char to,char temp);
int cishu(int n);


int main()
{
    char A,B,C;
    int n;
    while(scanf("%d",&n)!=EOF){
    hanoi(n,'A','C','B');
    printf("一共移动了%d步\n",cishu(n));
    
    system("pause");}
    return 0;

}
void hanoi(int n,char from,char to,char temp)
{
    if(n==1)
        printf ("%d:%c--->%c\n",n,from,to);
    else {
        hanoi(n-1,from,temp,to);
        
        printf ("%d:%c--->%c\n",n,from,to);
        hanoi(n-1,temp,to,from);
    }
}

int cishu(int n)
{
    if(n==1)
        return 1;
    if(n>1)
        return cishu(n-1)+1+cishu(n-1);
    if(n<1)
        return 0;
}

任务七

#include<stdio.h>
#include<stdlib.h>
#include<Windows.h>
int main(){
int a, b, i, j, count1, count2;
for (i = 2;i <= 20; i+=2)
{

    for (a = 2;a <= i/2; a++)
    {
        count1 = 0;
        for (j = 2;j <= a - 1;j++)
        {
              if (a% j==0)
              {
                  count1++;
                  break;
              }
        }
        if (count1 ==0)
        {
            count2 = 0;
            b=i-a;
            for (j= 2; j <= b- 1;j++)
            {
                if (b%j== 0)
                {
                    count2++;
                    break;
                }
            }
           if (count2 ==0)
           {
             printf("%d=%d+%d\n", i, a, b);
           }
        }
    }
}
system("pause");
             return 0;
                 }

 

 

 

任务八

 

#include <stdio.h>
#include<math.h>
long func(long s);
int main() {
    long s, t;
    printf("Enter a number:");
    while (scanf("%ld", &s) != EOF) {
        t = func(s);
        printf("new number is:%ld\n\n", t);
        printf("Enter a number:");
    }
    return 0;
}
long func(long s)
{
    int j, count = 0;
    long n=0;
    while (s != 0)
    {
        j = s % 10;
        s = s / 10;
        if (j % 2 != 0)
        {
            n += j * pow(10, count);
            count++;
        }
    }
    return n;

}