实验三

task1

#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, November~";
    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);
}

作用：

 

task2

 

#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;
    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;
}

 

 

task3

#include <stdio.h>
long long func(int n); 
int main() {
    int n;
    long long f;
    while (scanf_s("%d", &n) != EOF) {
        f = func(n); 
        printf("n = %d, f = %lld\n", n, f-1);
    }
    return 0;
}
long long func(int n) {

    if (n == 0)return 1;

    else
        return 2 * func(n - 1);
}

task4

 

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

task 5

#include <stdio.h>

int mul(int n,int m);

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

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

task6

#include <stdio.h>
#include <stdlib.h>

void hanoi(int n,char from,char temp,char to);
void moveplate(int n,char from,char to);

int count = 0;

int main ()
{
    int n;
    while(scanf("%d",&n) != EOF)
    {
        hanoi(n,'A','B','C');
        printf("\n一共移动了%d次\n",count);
        count = 0;
    }
    
    
    return 0;
}

void hanoi(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(int n,char from,char to)
{
    printf("%u:%c --> %c\n",n,from,to);
    count++;
}

task7

#include <stdio.h>

int is_prime(int n);

int main()
{
    int num,f;
    int stop = 0;
    int i = 2;
    
    while (i<20)
    {
        i += 2;
        for (int k = 2; k < i;k++)
        {
            num = i - k;
            f = is_prime(num);
            if (f)
            {
                printf("%d = %d + %d\n",i,k,num);
                stop = 1;
            }
            if (stop) break;        
        }
        stop =0;
    }
    
    return 0;
}

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

task8

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

long fun(long s); 

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

long fun(long s)
{
    int n;
    int num = 0;
    int count = 0;
    while (s != 0)
    {
        n = s % 10;
        if (n % 2 != 0)
        {
            num = pow(10,count) * n + num;
            count++; 
        }
        s /= 10;
    }
    return num;
}

task8