实验3

实验任务1

//3task1
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<windows.h>
#define N 80

void printText(int line,int col,char text[]);//函数声明
void printSpaces(int n);//函数声明 
void printBlankLines(int n);//函数声明

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

    srand(time(0));//以当前系统时间作为随机种子

    for(i=1;i<=10;++i)
    {
        line=rand()%25;
        col=rand()%80;
        printText(line,col,text);
        Sleep(1000);//暂停1000ms 
    }
return 0;
}
//打印n个空格
    void printSpaces(int n){
         int i;
         for(i=1; i<=n; ++i)
         printf(" ");
}
// 打印n行空白行
    void printBlankLines(int n)
{
    int i;

    for(i=1; i<=n; ++i)
    printf("\n");
}
//在第line行第col列打印一段文本 
    void printText(int line, int col, char text[])
{
        printBlankLines(line-1); // 打印n-1行空行
        printSpaces(col-1);
        printf("%s",text);
}

 

实验任务2

//3task2_1
#include <stdio.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));
        
        return 0;
 } 
 
 //函数定义
 long long fac(int n)
 {
     static long long p = 1;
     
     p = p * n;
     
     return p;
     
  } 

增加一行代码后截图

 

//3task2_2
//练习：局部static变量特性

#include <stdio.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);
    
    return 0;
 } 
 
 //函数定义
 int func(int a,int b)
 {
     static int m = 0, i = 2;
     
     i += m + 1;
    m = i + a + b;
    
    return m;
  } 

 

实验任务3

//3task3
#include <stdio.h>
long long fun(int n);

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

//函数定义
long long fun(int m)
{   
    int i;
    static long long p;
    for(i=0,p=0;i<m;i++)
    {
    p= 2*p + 1;}
    return p;
}
 

 

实验任务4

//3task4
#include <stdio.h>
#include <math.h>
void hanoi(unsigned int n,char from,char temp,char to);
void moveplate(unsigned int n,char from,char to);
int main()
{

    unsigned int n;
    int i;

    while(scanf("%u",&n)!=EOF)
    {
    hanoi(n,'A','B','C');
    i=pow(2,n)-1;
    printf("一共移动了%d次\n\n\n",i); 
}
    return 0;
 } 
 void hanoi(unsigned int n,char from,char temp,char to)
 {
     if(n==1)
        moveplate(n,from,to);
     else
     {
         hanoi(n-1,from,to,temp);
         moveplate(n,from,to);
         hanoi(n-1,temp,from,to);
     }
 }
 void moveplate(unsigned int n,char from,char to)
 {
     
     printf("第%u个盘子:%c-->%c\n",n,from,to);
     
 }

 

实验任务5

 

//3task5
#include <stdio.h>
#include <math.h>
#include <stdlib.h> 
int is_prime(int n);

int main()
{
    int n,p,q,x,y;
  for(n=4;n<=20;n+=2)
    {  
        p=1;
        do
        {
            p++;
            q=n-p;
            x = is_prime(p);
            y = is_prime(q);
        }
       while(x*y == 0);
        printf("%d = %d + %d\n",n,p,q);
    }

 return 0;
}

//函数定义
int is_prime(int n)
{
    int i;
for(i=2;i<sqrt(n);i++)
{
    int a;
    if(n%i == 0)
    return 0;
}
return 1;
 } 

 

实验任务6

//3task6
#include <stdio.h>
long fun(long s);//函数声明 

int main()
{
    long s, t;
    
    printf("Enter a number:");
    while(scanf("%ld",&s)!=EOF)
    {
        t = fun(s);//函数调用
        printf("new number is: %ld\n\n", t);
        printf("Enter a number: ");
         
     } 
     return 0;
}

long fun(long s)//函数定义
{
    int a;
    int b=0,c=1;
    while(s!=0)
    {
        a=s%10;
        if(a%2==0)
            b=b;
        else
        {
            b=b+a*c;
            c=c*10;
        }
        s=s/10;
    }
    return b;
}