task1
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define N 5
int main() {
int number;
int i;
srand(time(0)); // 以当前系统时间作为随机种子
for (i = 0; i < N; ++i) {
number = rand() % 100 + 1;
printf("20490042%04d\n", number);
}
return 0;
}
问题1：生成一个0~100之间的数
问题2：给学号填补两个0，凑够12位数
问题3：生成一个前面数字相同，且学号尾部为0到100的学号
task2
#include <stdio.h>
int main() {
int choice, quantity;
float total_price = 0, amount_paid, change;
while (1) {
printf("\n自动饮料售卖机菜单:\n");
printf("1. 可乐 - 3 元/瓶\n");
printf("2. 雪碧 - 3 元/瓶\n");
printf("3. 橙汁 - 5 元/瓶\n");
printf("4. 矿泉水 - 2 元/瓶\n");
printf("0. 退出购买流程\n");
printf("请输入饮料编号: ");
scanf("%d", &choice);
if (choice == 0)
break;
if (choice < 1 || choice > 4) {
printf("无效的饮料编号，请重新输入。\n");
continue;
}
printf("请输入购买的数量: ");
scanf("%d", &quantity);
if (quantity < 0) {
printf("购买数量不能为负数，请重新输入。\n");
continue;
}
switch (choice) {
case 1:
case 2:
total_price += 3 * quantity;
break;
case 3:
total_price += 5 * quantity;
break;
case 4:
total_price += 2 * quantity;
break;
}
printf("请投入金额: ");
scanf("%f", &amount_paid);
change = amount_paid - total_price;
printf("本次购买总价: %.2f 元\n", total_price);
printf("找零: %.2f 元\n", change);
total_price = 0;
}
printf("感谢您的购买，欢迎下次光临！\n");
return 0;
}
问题1：将下次购买所需支付的钱的基础值归零；如果没有删除这行，下次购买也需要花本次购买所花的钱
问题2：break直接跳出循环，continue会直接进行下一次循环而不执行接下来循环内的程序
问题3：不需要，如果choice不等于1到4程序将不会进行下去
task3
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
int main()
{
char color;
while (scanf("%c", &color) != EOF)
{
getchar();
switch (color)
{
case 'r':printf("stop!\n"); break;
case 'y':printf("wait a minute\n"); break;
case 'g':printf("go go go\n"); break;
default:printf("something must be wrong\n");
}
}
return 0;
}
task4
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
int main()
{
double spend,sum,max,min;
printf("输入今日开销，直到输入-1终止：\n");
scanf("%lf",&spend);
max = spend;
min = spend;
sum = spend;
while(1)
{
scanf("%lf", &spend);
if (spend == -1)
{
break;
}
else
{
sum = sum + spend;
if (spend >= max)
{
max = spend;
}
if (spend <= min)
{
min = spend;
}
}
}
printf("今日累计消费总额：%.1lf\n",sum);
printf("今日最高消费：%.1lf\n", max);
printf("今日最低消费：%.1lf\n", min);
return 0;
}
task5
#define _CRT_SECURE_NO_WARNINGS
#include<stdlib.h>
#include<time.h>
#include <stdio.h>
int main()
{
int number,guess,x;
printf("猜猜2025年4月那一天是你的lucky day\n你有三次机会，猜吧（1~30）,哈吉马路哟~~:");
srand(time(0));
number = rand() % 30 + 1;
for (x = 0; x < 3; ++x)
{
scanf("%d", &guess);
if (guess > number)
{
printf("你猜的日期晚了，lucky day has pass away\n");
printf("try again(1~30):");
}
else if (guess < number)
{
printf("你猜的日期早了，时辰未到\n");
printf("try again(1~30):");
}
else
{
printf("哇，猜中了，你好棒哦（棒读）\n");
break;
}
}
if (x == 3)
{
printf("次数用完了老铁，你是真的霉比(乐),你的幸运日在%d号呢", number);
}
return 0;
}
task6
#include <stdio.h>
int main()
{
int n,x,y,z;
printf("input n:");
scanf("%d", &n);
for (x = 1; x <= n; x++)
{
for (z = 1; z < x; z++)
{
printf("\t");
}
for (y=2*n+1-2*x;y>0;y--)
{
printf(" O\t");
}
printf("\n");
for (z = 1; z < x; z++)
{
printf("\t");
}
for (y = 2 * n+1 - 2*x; y > 0; y--)
{
printf("<H>\t");
}
printf("\n");
for (z = 1; z < x; z++)
{
printf("\t");
}
for (y = 2 * n+1 - 2*x; y > 0; y--)
{
printf("I I\t");
}
printf("\n");
}
return 0;
}
