实验三

任务1

#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); 
}

功能：输入十个“hi，April”，间隔1秒

任务二

2.1

#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! = %11d\n",i,fac(i));
        
        return 0;
}


long long fac(int n){
    static long long p = 1;
    
    p = p * n;
    
    return p;
}

2.2

#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;
}

static特性：再次调用时保留上次函数运行结束时的值

任务三

#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)
{
    long long a,b;
    if(n == 0)
    {
        a = 0;
    }else{
        b = 2*func(n-1)+1;
        a = b;
    }
    
    return a;
}

实验任务四

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

实验任务五

5.1

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

5.2

#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;
    while(y>0){
        s=s*x;
        y=y-1;
    } 
    while(y<0){
        s=s/x;
        y=y+1;
    }
    return s;
}

实验任务六

#include<stdio.h>
#include<math.h>
void hanoi(unsigned int n,char from,char temp,char to);//递归函数声明
void moveplate(unsigned int n,char from,char to);
int main()
{
    unsigned int n,i;
    while(scanf("%u",&n) != EOF)
    {
    hanoi(n,'A','B','C');
    i=pow(2,n)-1;
    printf("\n一共移动了:%d次\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7

#include <stdio.h> 
#include <math.h>
int is_prime(int n);
int main()
{
    int i, k, a[15], j = 0, l;
    for (k = 2; k <= 20; k++)
    {
        if (is_prime(k))
            a[j++] = k;
    }
    for (i = 2; i <= 10; i++)
    {
        for (l = 1; l <= 10; l++)
        {

            if (is_prime(2 * i - a[l - 1]))
            {
                printf("%d = %d + %d\n", (2 * i), a[l - 1], (2 * i - a[l - 1])); break;
            }

        }
    }
    return 0;
}
int is_prime(int n)
{
    int i, flag = 1;
    for (i = 2; i <= sqrt(n); i++)
    {
        if (n % i == 0) { flag = 0; break; }
    }
    return flag;
}

实验任务八

#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("nem number is: %ld\n\n",t);
        printf("Enter a number:");
    }
    
    return 0;
} 

long func(long s){
    long b=0,t=0;
    int a,m;
    while(s!=0){
        a=s%10;
        if(a%2!=0)
            b=10*b+a;
        s=s/10;
    }
    
    while(b!=0){
        m=b%10;
        t=10*t+m;
        b=b/10;
    }
    
    return t;
}