TASK1


1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <time.h> 4 5 #define N 5 6 7 int main() { 8 int number; 9 int i; 10 11 srand(time(0)); // 以当前系统时间作为随机种子 12 for(i = 0; i < N; ++i) { 13 number = rand() % 100 + 1; 14 printf("20490042%04d\n", number); 15 } 16 17 return 0; 18 }
ANS1
随机生成1~100之间的整数
ANS2
指定4位宽度输出,不足用0填充
ANS3
随机抽取5个学号后3位在1~100的学生学号
TASK2

1 #include <stdio.h> 2 3 int main() { 4 int choice, quantity; 5 float total_price = 0, amount_paid, change; 6 7 while (1) { 8 printf("\n自动饮料售卖机菜单:\n"); 9 printf("1. 可乐 - 3 元/瓶\n"); 10 printf("2. 雪碧 - 3 元/瓶\n"); 11 printf("3. 橙汁 - 5 元/瓶\n"); 12 printf("4. 矿泉水 - 2 元/瓶\n"); 13 printf("0. 退出购买流程\n"); 14 printf("请输入饮料编号: "); 15 scanf("%d", &choice); 16 17 if (choice == 0) 18 break; 19 20 if (choice < 1 || choice > 4) { 21 printf("无效的饮料编号,请重新输入。\n"); 22 continue; 23 } 24 25 printf("请输入购买的数量: "); 26 scanf("%d", &quantity); 27 28 if (quantity < 0) { 29 printf("购买数量不能为负数,请重新输入。\n"); 30 continue; 31 } 32 33 switch (choice) { 34 case 1: 35 case 2: 36 total_price += 3 * quantity; 37 break; 38 case 3: 39 total_price += 5 * quantity; 40 break; 41 case 4: 42 total_price += 2 * quantity; 43 break; 44 } 45 46 printf("请投入金额: "); 47 scanf("%f", &amount_paid); 48 49 change = amount_paid - total_price; 50 printf("本次购买总价: %.2f 元\n", total_price); 51 printf("找零: %.2f 元\n", change); 52 53 total_price = 0; 54 } 55 56 printf("感谢您的购买,欢迎下次光临!\n"); 57 return 0; 58 }
ANS1
将上一次的总价清零。去掉之后下一次购买时的总价会加上之前的总价
ANS2
使用break会直接跳转到该框内的程序末尾,在这里也就是直接结束程序;continue使用后会继续重新运行框内程序,直到手动结束
ANS3
没有必要。前面的case语句已经完全涵盖取值并被明确处理
TASK3

1 #include <stdio.h> 2 3 int main() { 4 char zifu; 5 6 while(scanf("%c", &zifu)!= EOF){ 7 switch(zifu){ 8 case 'g': 9 printf("GOGOGO\n"); 10 break; 11 case 'y': 12 printf("wait a minute\n"); 13 break; 14 case 'r': 15 printf("STOP\n"); 16 break; 17 default: 18 printf("sth must be wrong...\n"); 19 break; 20 } 21 while(getchar()!='\n'); 22 } 23 24 25 return 0; 26 }
TASK4

1 #include <stdio.h> 2 3 int main() { 4 double exp; 5 double total=0; 6 double max=0; 7 double min =20000; 8 9 printf("输入今日开销,直到输入-1终止:\n"); 10 while(1){ 11 scanf("%lf",&exp); 12 if(exp==-1){ 13 break; 14 } 15 total+=exp; 16 if(exp>max){ 17 max=exp; 18 } 19 if(exp<min){ 20 min=exp; 21 } 22 23 } 24 printf("今日累计消费总额:%.1f\n",total); 25 26 printf("今日最高一笔开销:%.1f\n",max); 27 28 printf("今日最小一笔开销:%.1f\n",min); 29 30 31 return 0; 32 }
TASK5

1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <time.h> 4 5 int main() { 6 srand((unsigned int)time(NULL)); 7 int Lucky=rand()%30+1; 8 int yh , chance = 3; 9 printf("猜猜25年4月哪一天是你的lucky day\n"); 10 while(chance > 0){ 11 printf("开始咯,你有3次机会,猜吧(1~30):\n"); 12 scanf("%d",&yh); 13 if (yh < Lucky){ 14 printf("你猜的日期早了,你的lucky day还没到呢\n,再猜"); 15 } 16 if (yh > Lucky){ 17 printf("你猜的日期晚了,你的lucky day在前面呢\n,再猜"); 18 } 19 if (yh == Lucky){ 20 printf("猜中了!\n"); 21 return 0; 22 } 23 24 chance--; 25 } 26 27 printf("次数用完了,告诉你,幸运日是&yh 号"); 28 return 0; 29 }
TASK6

1 #include <stdio.h> 2 #include<stdlib.h> 3 int main() 4 { 5 int a,i,m,n; 6 printf("input n: "); 7 scanf("%d",&n); 8 9 for(i=1;i<=n;++i){ 10 11 for(m = n - i + 1;m<n;++m) 12 printf("\t"); 13 14 for(a=0;a<2*(n-i)+1;++a) 15 printf(" O \t"); 16 printf("\n"); 17 18 for(m=n-i+1;m<n;++m) 19 printf("\t"); 20 21 for(a=0;a<2*(n-i)+1;++a) 22 printf("<H>\t"); 23 printf("\n"); 24 25 for(m=n-i+1;m<n;++m) 26 printf("\t"); 27 28 for(a=0;a<2*(n-i)+1;++a) 29 printf("I I\t"); 30 printf("\n"); 31 } 32 system("pause"); 33 return 0; 34 }