实验三

任务一：

程序源码：

#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);
}

该程序实现的功能：

 随机行随即列生成相应语句

任务二：

程序源码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;
}

运行截图：

程序源码：

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


long long fac(int n) {
    static long long p = 1;
    printf("p = %11d\n", p);
    p = p * n;
    
    return p;
}

运行截图：

程序源码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;
}

运行截图：

任务三:

程序源码：

#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 = %11d\n", n, f);
    }
    
    return 0;
}

long long func(int n){
    if (n==0)
    return 0;
    else
    return func(n-1)*2+1;
}

运行结果：

任务四：

 程序源码：

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

运行结果：

任务五：

程序源码：

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

运行结果：

任务六：

程序源码：

#include<stdio.h>
#include<math.h>
void hanoi(unsigned n ,char from ,char temp, char to);
void mp(unsigned nth, char from , char to);
int main()
{ unsigned n,k; char from='A',temp='B',to='C';
    while(scanf("%u",&n)!=EOF)
    {hanoi(n,from,temp,to);
    k=pow(2,n)-1;
    printf("一共移动盘子%u次\n",k);
    
    }
    return 0;
}
void hanoi(unsigned n ,char from ,char temp, char to)
{if(n==1)
     mp(n,from,to);
else{
    hanoi(n-1,from,to,temp);
    mp(n,from,to);
    hanoi(n-1,temp,from,to);
}
}
void mp(unsigned nth, char from , char to)
{printf("%u: %c --> %c\n",nth,from,to);
}

运行结果：

任务七：

程序源码：

#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;
}

运行结果：