实验三

#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,Novermber~";
    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);
}
void print_text(int line, int col, char text[])
{
    print_blank_lines(line - 1);
    print_spaces(col - 1);
    printf("%s", text);
}

以时间为种子，随机生成一个小于24的行和一个小于79的列，并每隔这么多距离打印一个text中的内容，共十次。

#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 = 1 + a + b;
    return m;
}

定义static变量，在程序运行时便会给变量分配存储空间，它的值会随着不同的运算改变。

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

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

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

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

#include<stdio.h>
#include<stdlib.h>
int is_prime(int n);

int main()
{
    int i, j,a;
    for (i = 1;i <= 20; ++i)
    {
        if (i % 2 == 0)
        {
            for (j = 2; j <i; j++) 
            {
                a = i - j;
                if (is_prime(a) && is_prime(j) && a != 0)
                {
                    printf("%d=%d+%d\n", i, j, a);
                    break;

                }
            }
        
        }
        else continue;
    }
}
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;
}

#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 ans [100], i,t=0,j,a;
    long sum=0;
    for (i = 0; i <= 100; i++)
    {
        a = s % 10;
        s = s / 10;
        if (a % 2 == 1)
        {
            ans[t] =a;
            t++;
        }
        else continue;
    }
    for (j = t-1;j >= 0;j--)
    {
        sum = sum * 10 + ans[j];
    }
    return sum;
}