實驗二

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

#define N 5

int main()
{
    int number;
    int i;

    srand(time(0));

    for (i = 0; i < N; ++i) {
        number = rand() % 65 + 1;
        printf("20238331%04d\n", number);
    }
    return 0;
}

#include <stdio.h>
int main()
{
	char colour;
	printf("請輸入交通信號燈的顏色：");
	while ((colour = getchar()) != EOF)
	{
		switch (colour)
		{
		case 'r':
			printf("stop!\n");
			break;
		case 'g':
			printf("go go go\n");
			break;
		case 'y':
			printf("wait a minute\n");
			break;
		default:
			printf("something must be wrong\n");
		}
		getchar();
	}
	return 0;
}

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

int main() {
    int number, m, i;
    srand(time(0));
    printf("猜猜2024年5月哪一天會是你的lucky day");
    number = rand() % 30 + 1;
    printf("\n");
    printf("開始嘍，你有三次機會，猜吧（1~31）：");
    scanf_s("%d", &m);
    for (i = 0; i < 2; ++i)
    {
        if (m > number)
        {
            printf("你猜的日期晚了，你的lucky day在前面哦\n再猜（1~31）：");
            scanf_s("%d", &m);
        }
        else if (m < number)
        {
            printf("你猜的日期早了，你的lucky day還沒到呢\n再猜（1~31）：");
            scanf_s("%d", &m);
        }
        else
        {
            printf("哇，猜中了：-）");
            break;
        }
    }
    if (i == 2)
        printf("次數用完啦。偷偷告訴你，5月你的lucky day是%d", number);
    return 0;
}

#include<stdio.h>
 int main()
 {
	 int n, a, i, up, down;
	 double s, ans;
	 ans = 0;
	 printf("請輸入正整數n和a:");
	 while (scanf_s("%d %d", &n, &a) != EOF)
		 {
		 for (i = 1, s = 0, down = 0; i <= n; i++)
			 {
			     up = i;
			     down = down * 10 + a;
			     ans = up * 1.0 / down;
			     s = s + ans;
			  }
		  printf("n=%d,a=%d,s=%f", n, a, s);
	 printf("\n請輸入正整數n和a:"); }
 return 0;
 }

![](https://img2024.cnblogs.com/blog/3405472/202404/3405472-20240415140358685-888898226.png)

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include<stdlib.h>
int main() {
    int n, i, k, j;
    printf("input n:");
    scanf("%d", &n);

    for (i = 0; i < n; i++)
    {
        for (j = 0; j < i; j++)
        {
            printf("\t");
        }
        for (k = 2 * (n - i) - 1; k > 0; k--)
        {
            printf(" O \t");
        }
        printf("\n");

        for (j = 0; j < i; j++)
        {
            printf("\t");
        }
        for (k = 2 * (n - i) - 1; k > 0; k--)
        {
            printf("<H>\t");
        }
        printf("\n");

        for (j = 0; j < i; j++)
        {
            printf("\t");
        }
        for (k = 2 * (n - i) - 1; k > 0; k--)
        {
            printf("I I\t");
        }
        printf("\n");
    }
    system("pause");
    return 0;
}