C Primer Plus 第6版 第七章 编程练习参考答案
编译环境VS Code+WSL GCC 源码请到文末下载 。 注意：本章部分题目有些超纲（回用到函数调用），不理解的同学可以先去看一下后面的知识点和注释。
/*第1题*************************/
#include<stdio.h>
#include<ctype.h>
int main()
{
char ch;
int space,new,others;
space = new = others = 0;
while ((ch = getchar()) != '#')
{
if(ch == ' ')
space++;
else if(ch == '\n')
new++;
else
others++;
}
printf("空格有：%d个\n换行有：%d个\n其他有：%d个\n",space,new,others);
return 0;
}
/*第2题*************************/
#include<stdio.h>
#include<ctype.h>
int main()
{
char arry[999]={0};
char ch;
int cnt = 0,i = 0;
while ((ch = getchar()) != '#'){
arry[cnt++] = ch;
}
for(i=1;i<cnt+1;i++){
if(isalnum(arry[i-1])||ispunct(arry[i-1]))
printf("\'%c\'-%-3d ",arry[i-1],arry[i-1]);
else
printf("\'?\'-%-3d ",arry[i-1]);
if(i != 0 && i%8 == 0)
putchar('\n');
}
putchar('\n');
return 0;
}
/*第3题*************************/
#include<stdio.h>
int main()
{
int s_num_sum,d_num_sum,s_num_cnt,d_num_cnt,input_num;
double s_num_avg,d_num_avg;
s_num_sum = d_num_sum = s_num_cnt = d_num_cnt = input_num = 0;
printf("请输入整数，输入0退出：");
do{
if(scanf("%d",&input_num) == 1 && input_num != 0){
//如果输入的是一个不为0的整数,将继续下面的操作（排除其他情况）
if(input_num%2 == 0){ //如果输入是双数
d_num_sum += input_num; //双数总和累加
d_num_cnt++; //双数个数++
}
else{
s_num_sum += input_num;
s_num_cnt++;
}
}
} while (input_num != 0);
s_num_avg = 1.0 * s_num_sum / s_num_cnt;
d_num_avg = 1.0 * d_num_sum / d_num_cnt;
printf("输入的偶数个数：%d\n输入的偶数平均值：%g\n输入的奇数个数：%d\n输入的奇数平均值：%g\n",
d_num_cnt,d_num_avg,s_num_cnt,s_num_avg);
return 0;
}
/*第4题*************************/
#include<stdio.h>
int main()
{
char arry[999]={0};
char ch;
int i=0,cnt=0;
printf("请输入字符，直到#停止：");
while ((ch = getchar()) != '#')
{
if(ch == '.'){
arry[i++]='!';
cnt++;
}
else if(ch == '!'){
arry[i++]='!';
arry[i++]='!';
cnt += 2;
}
else{
arry[i++]=ch;
}
}
arry[i]='\0';
printf("替换后为：\n%s\n",arry);
printf("进行了%d次替换\n",cnt);
return 0;
}
/*第5题*************************/
#include<stdio.h>
int main()
{
char arry[999]={0};
char ch;
int i=0,cnt=0;
printf("请输入字符，直到#停止：");
while ((ch = getchar()) != '#')
{
switch (ch)
{
case '.':
arry[i++]='!';
cnt++;
break;
case '!':
arry[i++]='!';
arry[i++]='!';
cnt += 2;
break;
default:
arry[i++]=ch;
break;
}
}
arry[i]='\0';
printf("替换后为：\n%s\n",arry);
printf("进行了%d次替换\n",cnt);
return 0;
}
/*第6题*************************/
#include<stdio.h>
int main()
{
char arry[999]={0};
char ch;
int i=0,cnt=0;
printf("请输入字符，直到#停止：");
while ((ch = getchar()) != '#')
{
if(ch == '.'){
arry[i++]='!';
cnt++;
}
else if(ch == '!'){
arry[i++]='!';
arry[i++]='!';
cnt += 2;
}
else{
arry[i++]=ch;
}
}
arry[i]='\0';
printf("替换后为：\n%s\n",arry);
printf("进行了%d次替换\n",cnt);
return 0;
}
/*第7题*************************/
#include<stdio.h>
#define BASE_TIME 10
#define OVER_TIME (BASE_TIME * 1.5)
#define BASE_TAX 0.15
#define ADD_TAX 0.2
#define OTHER_TAX 0.25
int main()
{ //总工作时间，总工资，净工资，总税收
float work_times,all_salary,clear_salary,all_tax;
printf("您一周工作了多少小时？\n");
scanf("%f",&work_times);
if(work_times > 40)
{
all_salary = (work_times * BASE_TIME) + (work_times - 40) * OVER_TIME;
}
else
{
all_salary = work_times * BASE_TIME;
}
if(all_salary <= 300)
{
all_tax = all_salary * BASE_TAX;
}
else if(all_salary <= 450 && all_salary >300)
{
all_tax = 300 * BASE_TAX + (all_salary - 300) * ADD_TAX;
}
else
{
all_tax = 300 * BASE_TAX + 150 * ADD_TAX + (all_salary - 450) * OTHER_TAX;
}
clear_salary =all_salary - all_tax;
printf("总工作时间:%g\n总工资:%g\n净工资:%g\n总税收:%g\n",work_times,all_salary,clear_salary,all_tax);
return 0;
}
/*第8题*************************/
#include<stdio.h>
//#define BASE_TIME 10
#define OVER_TIME (BASE_TIME * 1.5)
#define BASE_TAX 0.15
#define ADD_TAX 0.2
#define OTHER_TAX 0.25
int main()
{ //总工作时间，总工资，净工资，总税收
float work_times,all_salary,clear_salary,all_tax,BASE_TIME;
int case_num;
while (1)
{
printf("*************************************\n\n");
printf("请输入数子对应的工资等级，输入5退出程序：\n");
printf("1) $8.75/hr 2) $9.33/hr\n");
printf("3) $10.0/hr 4) $11.2/hr\n");
printf("5) exit\n");
printf("*************************************\n");
if((scanf("%d",&case_num) != 1) || !(case_num <= 5 && case_num >= 0))
//排除非数字和不在范围内
{
printf("输入错误，请重新输入！\n");
continue;//跳过下面的内容，重新开始循环
}
switch (case_num)
{
case 1:
BASE_TIME =8.75;
break;
case 2:
BASE_TIME =9.33;
break;
case 3:
BASE_TIME =10;
break;
case 4:
BASE_TIME =11.2;
break;
case 5:
default:
printf("程序退出！\n");
goto end;//跳出两重循环直接到程序结尾
break;
}
break;//结束while循环
}
printf("您一周工作了多少小时？\n");
scanf("%f",&work_times);
if(work_times > 40)
{
all_salary = (work_times * BASE_TIME) + (work_times - 40) * OVER_TIME;
}
else
{
all_salary = work_times * BASE_TIME;
}
if(all_salary <= 300)
{
all_tax = all_salary * BASE_TAX;
}
else if(all_salary <= 450 && all_salary >300)
{
all_tax = 300 * BASE_TAX + (all_salary - 300) * ADD_TAX;
}
else
{
all_tax = 300 * BASE_TAX + 150 * ADD_TAX + (all_salary - 450) * OTHER_TAX;
}
clear_salary =all_salary - all_tax;
printf("总工作时间:%g\n总工资:%g\n净工资:%g\n总税收:%g\n",work_times,all_salary,clear_salary,all_tax);
end:return 0;
}
/*第9题*************************/
#include<stdio.h>
#include<math.h>
int main()
{
int ipt,i,j;
printf("请输入一个大于0的数：");
while ((scanf("%d",&ipt)!=1) && (ipt <= 0))
{
printf("输入错误！\n");
printf("请输入一个大于0的数：");
}
if(ipt<4)
{
for(i=1;i<=ipt;i++)
printf("%-4d",i);
}
else
{
for(i=1;i<4;i++)
printf("%-4d",i);
for(i=4;i<ipt+1;i++){
for(j=2;j<i;j++){
if(i%j == 0){
break;
}
}
if(j == i){
printf("%-4d",i);
}
}
}
putchar(10);
return 0;
}
/*第10题*************************/
#include<stdio.h>
//#define class 10
#define CLASS_1 17850
#define CLASS_2 23900
#define CLASS_3 29750
#define CLASS_4 14875
#define BASE_TAX 0.15
#define OVER_TAX 0.28
int main()
{ //类别，总工资，总税收
float base,all_salary,all_tax;
int case_num;
while (1)
{
printf("------------------------------------------------\n");
printf("请输入数子对应的类别，输入5退出程序：\n");
printf("------------------------------------------------\n");
printf("1) 单身 17850$按15%%计，超出部分按28%%计算\n");
printf("2) 户主 23900$按15%%计，超出部分按28%%计算\n");
printf("3) 已婚,共有 29750$按15%%计，超出部分按28%%计算\n");
printf("4) 单身 14875$按15%%计，超出部分按28%%计算\n");
printf("5) exit\n");
printf("------------------------------------------------\n");
if((scanf("%d",&case_num) != 1) || !(case_num <= 5 && case_num >= 0))
//排除非数字和不在范围内
{
printf("输入错误，请重新输入！\n");
while (getchar() != '\n');//清空输入缓存
continue;//跳过下面的内容，重新开始循环
}
switch (case_num)
{
case 1:
base = CLASS_1;
break;
case 2:
base = CLASS_2;
break;
case 3:
base = CLASS_3;
break;
case 4:
base = CLASS_4;
break;
case 5:
default:
printf("程序退出！\n");
goto end;//跳出两重循环直接到程序结尾
break;
}
break;//结束while循环
}
while (1)
{
printf("您的收入是多少？输入Q退出：\n");
while(scanf("%f",&all_salary) != 1){
printf("程序退出！\n");
goto end;//跳出两重循环直接到程序结尾
}
if(all_salary <= base)
{
all_tax = all_salary * BASE_TAX;
}
else
{
all_tax = base * BASE_TAX +(all_salary - base) * OVER_TAX;
}
printf("您的总税收为:%g$\n",all_tax);
}
end:return 0;
}
/*第11题*************************/
#include<stdio.h>
//#define class 10
#define YANG_LI 2.05
#define TIAN_CAI 1.05
#define HUOLUO_BO 1.19
double yl_weight = 0,tc_weight = 0,hlb_weight = 0;
double yl_prices = 0,tc_prices = 0,hlb_prices = 0,all_prices = 0;
double get_weight(int case_class);
void show_info();
int user_ui();
int main()
{
user_ui();
return 0;
}
double get_weight(int case_class)//传入需要购买的品种
{
double weight=0;
printf("您要购买多少");
switch (case_class)
{
case 1:
printf("洋蓟");
break;
case 2:
printf("甜菜");
break;
case 3:
printf("胡萝卜");
break;
default:
printf("???");
break;
}
printf("(单位/磅)？输入0退回：\n");
while(scanf("%lf",&weight) != 1||weight < 0){//排除非数字和不在范围内
while (getchar() != '\n');//清空输入缓存
printf("输入错误，请重新输入！\n");
}
return weight;
}
void show_info()
{
double all_weight,weight_prices,free_prices = 0;
yl_prices = yl_weight * YANG_LI;
tc_prices = tc_weight * TIAN_CAI;
hlb_prices = hlb_weight * HUOLUO_BO;
all_prices = yl_prices + tc_prices + hlb_prices;
all_weight = yl_weight + tc_weight + hlb_weight;
if(yl_weight > 0){printf("您已购买洋蓟：%g 磅，%g 美元\n",yl_weight,yl_prices);}
if(tc_prices > 0){printf("您已购买甜菜：%g 磅，%g 美元\n",tc_weight,tc_prices);}
if(hlb_prices > 0){printf("您已购买胡萝卜：%g 磅，%g 美元\n",hlb_weight,hlb_prices);}
if(all_prices > 0){printf("您已购买%g 美元\n",all_prices);}
if(all_weight <= 5){
weight_prices = 6.5;
}
else if(all_weight > 5 && all_weight <= 20){
weight_prices = 14;
}
else
{
weight_prices = 14 + (all_weight-20)*0.5;
}
if(all_prices >= 100){
free_prices = all_prices * 0.05;
printf("已为您优惠%g 美元\n",free_prices);
}
printf("合计重量：%g 磅，共需运费：%g 美元，合计支付价格：%g 美元\n",
all_weight,weight_prices,all_prices - free_prices + weight_prices);
}
int user_ui()
{
int case_num;
while (1)
{
printf("------------------------------------------------\n");
printf("欢迎光临ABC邮购杂货店！\n");
printf("------------------------------------------------\n");
printf("1) 洋蓟 2.05美元/磅\n");
printf("2) 甜菜 1.15美元/磅\n");
printf("3) 胡萝卜 1.09美元/磅\n");
printf("4) exit\n");
printf("------------------------------------------------\n");
printf("您要购买什么？输入4退出程序：\n");
printf("------------------------------------------------\n");
if((scanf("%d",&case_num) != 1) || !(case_num <= 4 && case_num >= 0))
//排除非数字和不在范围内
{
printf("输入错误，请重新输入！\n");
while (getchar() != '\n');//清空输入缓存
continue;//跳过下面的内容，重新开始循环
}
switch (case_num)
{
case 1:
yl_weight += get_weight(case_num);
//debug printf("TEST:%g\n",yl_weight);
show_info();
break;
case 2:
tc_weight += get_weight(case_num);
show_info();
break;
case 3:
hlb_weight += get_weight(case_num);
show_info();
break;
case 4:
default:
printf("程序退出！\n");
goto end;//跳出两重循环直接到程序结尾
break;
}
}
end:return 0;
}
