李湘楠实验3

//task1.c
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <windows.h>
#define N 80

void print_text(int line, int col, char text[]);   //函数声明
void print_spaces(int n);  //函数声明
void print_blink_lines(int n);   //函数声明

int main()
{
    int line, col, i;
    char text[N] = "hi,April1~";

    srand(time(0));//以当前系统时间作为随机种子

    for (i = 1; i <= 10; ++i)
    {
        line = rand() % 25;
        col =  rand() % 80;
        print_text(line, col, text);
        Sleep(1000);  //暂停1000ms
    }

    return 0;
}

//打印n个空格
void print_spaces(int n)
{
    int i;

    for (i = 1; i <= n; ++i)
        printf(" ");
}

//打印n行空白行
void print_blank_lines(int n)
{
    int i;

    for (i = 1; i <= n; ++i)
        printf("\n");
}

//在第line行第col列打印一段文本
void print_text(int line, int col, char text[])
{
    print_blank_lines(line - 1);    //打印（line-1）行空行
    print_spaces(col - 1);         //打印（col-1)列空格
    printf("%s", text);           //在第line行、col列输出text中字符串
}

作用：输入“hi，April”，每个”hi，April“间隔随机line-1行和col-1个空格

/task2_1.c

//利用局部static变量的特性，计算阶乘

#include <stdio.h>
long long fac(int n); //函数声明

int main()
{
    int i, n;

    printf("Enter n: ");
    scanf_s("%d", &n);

    for (i = 1; i <= n; ++i)
        printf("%d! = %11d\n", i, fac(i));

    return 0;
}

//函数定义
long long fac(int n)
{
    static long long p = 1;
    printf("p = %11d\n", p);
    p = p * n;

    return p;
}

//task2_2.c

//练习：局部static变量特性

#include<stdio.h>
int func(int, int);  //函数声明

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;
}

//函数定义
int func(int a, int b)
{
    static int m = 0, i = 2;

    i += m + 1;
    m = i + a + b;

    return m;
}

 

 

 static静态储存变量，不会重复给变量赋相同的值，仅赋值一次

//task3.c
#include <stdio.h>
long long func(int n);   //函数声明

int main()
{
    int n;
    long long f;

    while (scanf_s("%d",&n) != EOF)
    {
        f = func(n); //函数声明
        printf("n = %d,f = %11d\n", n, f);
    }
    return 0;
}

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

//task4.c

#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;
}

//函数定义
int func(int n, int m)
{
    if (m == n || m == 0)
        return 1;
    else if (m > n)
        return 0;
    else
        return func(n - 1, m) + func(n - 1, m - 1);
}

 

//task5_1.c
#include <stdio.h>
#include <math.h>
double mypow(int x, int y);    //函数声明

int main() {
    int x, y;
    double ans;

    while (scanf_s("%d%d", &x, &y) != EOF) {
        ans = mypow(x, y);   //函数调用
        printf("%d的%d次方: %g\n\n", x, y, ans);
    }

    return 0;
}

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

//task6.c
#include <stdio.h>
#include<math.h>
void hanoi(unsigned int n, char from, char temp, char to);
void moveplate(unsigned int n, char from, char to);

int count;
int main()
{
    unsigned int n;
    while (scanf_s("%u", &n) != EOF)     /*输入盘子数目*/
    {
        count = 0;
        hanoi(n, 'A', 'B', 'C');
        printf("\n");
        printf("一共移动了%d次\n\n", count);
    }
    return 0;
}

void hanoi(unsigned int n, char from, char temp, char to)
{
    if (n == 1)
    {
        count++;
        moveplate(n, from, to);
    }
    else
    {
        hanoi(n - 1, from, to, temp); /*n-1个盘子从A以C为中转移到B上*/
        count++;
        moveplate(n, from, to);         /*将盘子n从A移到C上*/
        hanoi(n - 1, temp, from, to);   /*将n-1个盘子从B以A为中转移到C上*/
    }
}

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

//task7.c
#include<stdio.h>
#include<math.h>
int is_prime(int n);

int main()
{
    int n,m,p;
    for (n = 4; n <= 20; n += 2)
    {
        for (m = 1; m < 7; ++m)
        {
            p = n - m;
            if (is_prime(m) * is_prime(p) != 0)
                printf("%d=%d+%d\n", n, m, p);
        }
    }
    return 0;
}

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

//task8.c
#include<stdio.h>
#include<math.h>
long func(long s);    //函数声明

int main()
{
    long s, t;
    printf("Enter a number: ");
    while (scanf_s("%d", &s) != EOF)
    {
        t = func(s);   //函数调用
        printf("new number is: %d\n\n", t);
        printf("Enter a number: ");
    }
    return 0;
}

//函数定义
long func(long s)
{
    long n = 0; 
    int t, m = 0;
    while (s != 0);
    {
        t = s % 10;
        s = s / 10;
        if (t % 2 != 0)
        {
            n = n + t * pow(10, m);
            m++;
        }
    }
    return n;
}