实验三

task1

源代码

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

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

 } 

这个代码的功能是做出跳动的字符小人的动画。

task2

源代码1

//利用局部statuc变量的特性，计算阶乘

#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;
    printf("p=%lld\n",p);
    return p;
}

 源代码2

#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;
    
} 


int func(int a,int b){
    static int m=0,i=2;
    
    i+=m+1;
    m=i+a+b;
    
    return m;
} 

 结果与猜想一致。

task3

源代码

#include <stdio.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);
        
    }
    return 0;
} 

//函数定义
//函数补足
long long func(int n){
    long long s;
    
    if(n==1)return 1;
      else
        return (2*func(n-1)+1);
        
    
    
    
        
}

task4

源代码

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

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

int func(int n,int m){
    
    if(m>n)
      return 0;
    else if(m==n||m==0)
      return 1;
    else
      return (func(n-1,m)+func(n-1,m-1));
}

task5

源代码1

#include <stdio.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);
        
    }
    
    return 0;
}

double mypow(int x,int y){
    double s=1.0;
    int i;
    if(y>0)
      for(i=1;i<=y;i++) 
         s=s*x;
         
    if(y==0||x==1)
       s=1.0;
      
    if(y<0)
      for(i=-1;i>=y;i--)
         s=s/x;
     
return s;  
}

源代码2

#include <stdio.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);
        
    }
    
    return 0;
}


double mypow(int x,int y){
    double s=1.0;
    int i;
    if(y>0)
      s=x*mypow(x,y-1);
    if(y==0)
      
      s=1.0;
    
    if(y<0)
      s=mypow(x,y+1)/x;
    return s;  
}

task6

源代码

#include <stdio.h>
void hanoi(unsigned int n,char form,char temp,char to);
void moveplate(unsigned int n,char from,char to);
int count=0;
int main(){
    unsigned int n;
    int count1=0;
    while(scanf("%u",&n)!=EOF){
        count=count-count1;
        hanoi(n,'A','B','C');
        printf("一共移动了%d次\n",count); 
        count1=count;
        
    }
    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("%u:%c-->%c\n",n,from,to);
    count++;
    
} 

task7

源代码

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

#define N 10000

int is_prime(int n);
void separateeven(int n);

int isprime[N+1];

int main(){
    int a,b,m,i;
    
    scanf("%d%d",&a,&b);
    if(a%2!=0)
    a++;
    is_prime(N);
    printf("4=2+2\n");
    for(i=a;i<=b;i+=2)
       separateeven(i);
    return 0;
    
}

int is_prime(int n){
    int i,j;
    for(i=0;i<=n;i++)
       isprime[i]=1;
       
    isprime[0]=isprime[1]=0;
    int temp=(int)sqrt(n);
    
    for(i=2;i<=temp;i++)
       if(isprime[i])
         for(j=2*i;j<=n;j+=i)
            isprime[j]=0;
            
}

void separateeven(int n){
    int i;
    for(i=3;i<=n/2;i++)
       if(isprime[i]&&isprime[n-i])
       {
           printf("%d=%d+%d\n",n,i,n-i);
           break;
           
       }
}

task8

源代码

#include <stdio.h>
#include<math.h>   
long fun(long s); 
int main() {
    long s, t;
    printf("Enter a number: ");
    while (scanf_s("%ld", &s) != EOF) 
    {
        t = fun(s); 
        printf("new number is: %ld\n\n", t);
        printf("Enter a number: ");
    }
    return 0;
}

long fun(long s)
{
    long a,count=0,b=0;
    
    do
    {
        a = s % 10;
        if (a % 2 != 0)
        {
            b = b + a*pow(10,count);
            count++;
        }
        s = s / 10;
    } while (s != 0);
    return b;
}