实验3

实验任务1

实验源代码

#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);
}

结论：代码实现了随机生成10个hi April~

实验任务2

实验源代码

#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; 
} 

long long fac(int n){
    static long long p = 1;
    printf("p = %lld\n", p);
    p = p * n;
    
    return p;
}

#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;   
}

运行结果

结论

static的作用是使用时保留函数调用后的数值并在下一次函数调用的时候使用

实验任务3

实验源代码

#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;
}

long long func(int n){

    if(n == 1)
       return 1;
    else
       return 2*func(n-1)+1;

}

运行结果

 实验任务4

实验源代码

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

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

运行结果

实验任务5

实验源代码

#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 ans=1.0;
    if(y>=0)
    {for(int i = 1;i<=y;i++){
        ans = ans*x;
    } }
    else{
        for(int i = 1;i<=-y;i++){
            ans = ans/x; 
        }
    }
    return ans;
    }

#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){
    if(y == 0)
    return 1.0;
    if(y<0)
    return 1.0/mypow(x,-y);
    if(y>0) 
    return 1.0*x*mypow(x,y-1);
}

运行结果

实验任务6

实验源代码

#include<stdio.h>
#include<stdlib.h>
void hanoi(unsigned int n, char from,char temp,char to);
void moveplate(unsigned int n, char from,char to);
int ans;

int main()
{
    unsigned int n;

    while(scanf("%u", &n)!=EOF) {
    ans = 0;
    hanoi(n, 'A','B','C');
    printf("一共输入了%d次\n",ans);
    }
    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){
 
     ans++;
     printf("%u:%c-->%c\n",n,from,to);
 }

运行结果

实验任务7

实验源代码

#include<stdio.h>
int is_prime(int n);
int main(){
int n, m;
    for(n = 4;n<=20;n=n+2)
      for(m = 2;m<=20;m++)
       {
          if(is_prime(m)==1&&is_prime(n-m)==1)
          {
           printf("%d = %d + %d\n",n,m,n-m); break;
           }
           else 
           continue; 
        }
    
return 0;    
}
int is_prime(int n)
{

        for(int i = 2;i <= n;i++)
    {
    if(n%i==0&&i == n)
    {
    return 1 ;break;}
    if(n%i==0&&i!=n)
    return 0;
}

}

运行结果

实验任务8

实验源代码

#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)
{
    long a,b = 0,c = 0，d;
    for(;s!=0;)
{
    a = s%10;
    s = s/10;
    if( a%2 != 0)
       b = b*10 + a;
    }
    
    for( ;b!=0;)
       {
      d = b%10;
       b = b/10;
       c = c*10+d;  }
    return c;
      
}

运行结果