实验2——c语言分支与循环基础应用编程

task1

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

#define N 5
#define N1 374
#define N2 465

int main()
{
    int number;
    int i;

    srand(time(0));

    for (i = 0; i < N; i++)
    {
        number = rand() % (N2 - N1 + 1) + N1;
        printf("202383290409%04d\n", number);/*那个是谁的学号：）*/
    }
    return 0;
}

/*随机生成五个数，这些数在N1到0500之内*/
/*功能：在统一学号后生成五个随机数，阿是班号还是抽签顺序？*/

 

 

 

task2

#include<stdio.h>;
#include<stdlib.h>;
int main()
{
    char n;

    while (scanf("%c", &n) != EOF)
    {
        getchar();/*不要再忘了！！！*/
        switch (n)
        {
        case 'y':
            printf("wait a minute\n"); break;
        case 'g':
            printf("go go go\n"); break;
        case 'r':
            printf("stop!\n"); break;
        default:
            printf("something must be wrong...\n");
        }
    }

    system("pause");
    return 0;
}

 

 

task3

#include<stdlib.h>
#include<stdio.h>
#include<time.h>
int main()
{
    int a;/*随机数*/
    int n = 0; int i;
    srand((unsigned)time(NULL));/*通过 srand() 函数来重新“播种”*/
    a = rand()%30+1; /*可以看成两个部分：rand()%30是产生0~29的随机数，后面的+1保证a最小只能是1*/
    printf("赛博神婆上线，输入1~30中的一个数字查询您的幸运日~\n");
    printf("但是您只有三次机会~\n");
    for (i = 1; i <= 3; i++)
    {
        printf("深呼吸，与赛博宇宙进行能力量交换，追随心中的意志输入一个数字：\n");
        scanf("%d", &n);
        if (n < a)
        {
            printf("早咯~\n");
            printf("机会只剩下%d咯~~~\n", 3 - i);
        }
        else if (n > a)
        {
            printf("晚咯~\n");
            printf("机会只剩下%d咯~~~\n", 3 - i);
        }
        else if (n == a)
        {
            printf("猜对咯！！!\n"); exit(0);
        }
    }
    printf("其实每天都是您的幸运日！");
        system("pause");
    return 0;

}

 

 

task4

#include<stdio.h>
#include<stdlib.h> 
double sum10_16(int n, int a);
int main()
{
    int n = 0, a = 0;
    while (scanf("%d", &n) != EOF)
    {
        scanf("%d", &a);
        printf("%lf\n", sum10_16(n, a));
    }
    system("pause");
    return 0;


}
double sum10_16(int n, int a)
{
    double s = 0; double b = 1; double c = 1; int i;
    for (i = 1; i <= n; i++)
    {
        s = s + i/(a*c);
        c = c * 10 + 1;
    }
    return s;
}

 

task5

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int column, line;
    for (column = 1; column <= 9; column++)
    {
        for (line = 1; line <= column; line++)
        {
            printf("%dx%d=%3d  ", line, column, line * column);
        }
        printf("\n");
    }
    system("pause");
    return 0;
}

 

 

task6

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int n = 0;
    int i;
    printf("输入您需要的小人行数:");
    scanf("%d", &n);
    for (i = 1; i <= n; i++)
    {
        int l;
        for (l = 1; l <= 2 * i - 2; l++)
        {
            printf("   ");
        }
        int head;
        for (head = 1;head <= 2 * n - 2 * i + 1; head++)
        {
            printf(" O    ");
        }
        printf("\n");
        for (l = 1; l <= 2 * i - 2; l++)
        {
            printf("   ");
        }
        int body;
        for (body = 1; body <= 2 * n - 2 * i + 1; body++)
        {
            printf("<H>   ");
        }
        printf("\n");
        for (l = 1; l <= 2 * i - 2; l++)
        {
            printf("   ");
        }
        int leg;
        for (leg = 1; leg <= 2 * n - 2 * i + 1; leg++)
        {
            printf("I I   ");
        }
        printf("\n");
    }
    system("pause");
    return 0;
}

 注意点：

1.getchar()

2.EOF———  -1

3.时间种子（time待看）

4.srand用法

5.实验六待改进（用递归做）