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_text(int line, int col, char text[]) 
    {
    print_blank_lines(line-1); 
    print_spaces(col-1); 
    printf("%s", text);
    }
    void print_blank_lines(int n) {
    int i;
    for(i = 1; i <= n; ++i)
    printf("\n");
    }
    void print_spaces(int n){
    int i;
    for(i = 1; i <= n; ++i)
    printf(" ");
    }

随机生成hi，November~

task2

#include <stdio.h>
long long fac(int n);

int main() 
{
    int i, n;
    printf("Enter n: ");
    scanf_s("%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>
long long fac(int n);

int main() 
{
    int i, n;
    printf("Enter n: ");
    scanf_s("%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;
}

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);
    }
    return 0;
}
long long func(int n) {
    int i;
    long long f=0;
    for (i = 0; i < n; i++)
    f = 2 * (f + 1) - 1;
    return f;

}

task4

#include <stdio.h>
int func(int n, int m);
int main()
{
    int n, m;
    while (scanf_s("%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)
        return 0;
    else if (m == 0 || m == n)
        return 1;
    else if (m == 1)
        return n;
    else
        return ans = func(n - 1, m) + func(n - 1, m - 1);
}

task5

#include <stdio.h>
int mul(int n, int m);
int main() {
    int n, m;
    while (scanf_s("%d%d", &n, &m) != EOF)
        printf("%d * %d = %d\n", n, m, mul(n, m));
    return 0;
}

int mul(int n, int m)
{
    int x = 0, i;
    for (i = 0;i < n;i++)
      x = x + m;
    return x;
}

task6

#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 i = 0;
int main()
{
    unsigned int n;
    while (scanf_s("%u", &n) != EOF)
    {
        hanoi(n, 'A', 'B', 'C');
        printf("一共移动了%d次\n", i);
    }
    system("pause");
    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)
{
    i = i++;
    printf(" % u: % c--> % c\n", n, from, to);
}

task7

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int is_prime(int n);
int main()
{
    int a, b, c;
    for (a = 4; a <= 20; a = a + 2)
    {
        for (b = 2; b <= a; b++)
        {
            c = a - b;
            if (is_prime(b) && is_prime(c))
            {
                printf("%d=%d+%d\n", a, b, c);
                break;
            }
        }
    }
    return 0;
}

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

task8

#include <stdio.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)
{
    int a, b=1, c = 0;
    while(s>0)
    {
        a = s % 10;
        s = s / 10;
        if (a % 2 != 0)
        {
            c=c + a*b;
            b = b * 10;
        }
    }
    return c;
}