C Primer Plus（第六版）第八章 编程练习答案
作者：互联网
前言：这章是昨日刚打完的，其实第五题不是很满意，我也有点搞的一头雾水，当然其他章肯定有点小细节问题我还没发现，突然想起作者写到的有句话“不管你的程序提示打完多好，总会有人吐槽这个程序有多烂”，前几个我输入验证做的不是很完美（其实是当时有点烦就懒得做了），如被小伙伴学习参考，My pleasure.
仅供参考，新手勿喷。
CH08 Code answer 1:
#include <stdio.h>
#include <string.h>
int main(void)
{
char ch;
int count = 0;
while((ch = getchar()) != EOF) //这里会把换行符也读取
count++;
printf("%d",count);
} CH08 Code answer 2:
#include <stdio.h>
int main()
{
char ch;
int count = 0;
while((ch = getchar()) != EOF) //有个问题就是一换行就触发了
{
count++;
if(ch < ' ')
{
if(ch == '\t')
printf("\\t-%d ",ch);
else if(ch == '\n')
printf("\\n-%d ",ch);
else
printf("^%c-%d ",ch+64,ch);
}
else
printf("%c-%d ",ch,ch);
count%10 == 0 ? count=0,printf("\n") : count ;
}
} CH08 Code answer 3:
#include <stdio.h>
#include <ctype.h>
int main(void)
{
char ch;
int lower_count=0,upper_count=0;
while((ch = getchar()) != EOF)
{
if(islower(ch))
lower_count++;
else if(isupper(ch))
upper_count++;
}
printf("upper:%d lower:%d",lower_count,upper_count);
}CH08 Code answer 4:
#include <stdio.h>
#include <ctype.h>
int main(void)
{
int later_count,word_count,flag;
char ch;
later_count=word_count=flag=0;
while((ch = getchar()) != EOF)
{
if((isupper(ch) || islower(ch)) && !ispunct(ch))
{
later_count++;
flag = 1;
}
else if(isspace(ch) && flag == 1)
{
word_count++;
flag = 0;
}
}
printf("later:%d word:%d avg:%f",later_count,word_count,(float)later_count/(float)word_count);
}CH08 Code answer 5:
#include <stdio.h>
int main(void)
{
int low=0,high=100;
int guess = (high+low)/2;
char ch;
printf("Pick an integer from 1 to 100. I will try to guess ");
printf("it.\nRespond with a y if my guess is right and with");
printf("\nan n if it is wrong.\n");
printf("Uh...is your number %d?\n", guess);
while ((ch = getchar()) != 'y') /* get response, compare to y */
{
if(ch == 'h')
{
low = 0;
high = guess;
guess = (low+high)/2;
printf("Well, then, is it %d?\n", guess);
}
else if(ch == 'l')
{
low = guess;
high = 100;
guess = (low+high)/2;
printf("Well, then, is it %d?\n", guess);
}
while(getchar() != '\n')
continue;
}
printf("I knew I could do it!\n");
return 0;
}CH08 Code answer 6:
#include <stdio.h>
#include <ctype.h>
int main(void)
{
char ch;
while( isspace(ch = getchar()) ) //获取第一个非空字符
continue;
putchar(ch); //输出第一个字符
while(getchar() != '\n') //将多余的缓冲区输入排除
continue;
}CH08 Code answer 7:
这个是修改之前的程序，所以有些宏定义还留着。
#include <stdio.h>
#include <ctype.h>
#define SALARY 10
#define OVERTIME 40
#define Q300 0.15
#define X150 0.2
#define OM 0.25
#define r1 8.75
#define r2 9.33
#define r3 10.00
#define r4 11.20
void Print(void);
char get_choice(void);
char get_first(void);
int main(void)
{
float money;
int ho;
char choice;
float sa;
while((choice = get_choice()) != 'q')
{
switch (choice)
{
case 'a':
sa = r1;
break;
case 'b':
sa = r2;
break;
case 'c':
sa = r3;
break;
case 'd':
sa = r4;
break;
}
printf("请输入你工作了多少小时:");
scanf("%d",&ho);
if(ho > 40)
money = (ho-40)*1.5*sa + 40*sa;
else
money = ho*sa;
if(money <= 300)
money = money - Q300 * money;
else if(money <= 450)
money = money - ((money-300)*X150 + 300 * Q300);
else
money = money - ((money-450)*OM + 150*X150 + 300*Q300);
printf("你的工资为%f\n",money);
}
printf("bye!");
}
void Print(void)
{
printf("*****************************************************************\n");
printf("Enter the number corresponding to the desired pay rate or action:\n");
printf("a) $8.75/hr b) $9.33/hr\n");
printf("c) $10.00/h d) $11.20/hr\n");
printf("q) quit\n");
printf("*****************************************************************\n");
printf("请选择:");
}
char get_first(void)
{
char ch;
while( isspace(ch = getchar()) ) //获取第一个非空字符
continue;
//putchar(ch); //输出第一个字符
while(getchar() != '\n') //将多余的缓冲区输入排除
continue;
return ch;
}
char get_choice(void)
{
char ch;
Print();
ch = get_first();
while( (ch < 'a' || ch > 'd') && ch != 'q' )
{
printf("please respond with a, b, c, d, or q!");
ch = get_first();
}
return ch;
}CH08 Code answer 8:
#include <stdio.h>
#include <ctype.h>
char get_choice(void);
char get_first(void);
float get_float(char choice);
int main(void)
{
float a,b;
char choice;
while( (choice = get_choice()) != 'q')
{
printf("Enter first number:");
a = get_float(choice);
printf("Enter second number:");
b = get_float(choice);
switch(choice)
{
case 'a':
printf("%f + %f = %f\n",a,b,a+b);
break;
case 's':
printf("%f - %f = %f\n",a,b,a-b);
break;
case 'm':
printf("%f * %f = %f\n",a,b,a*b);
break;
case 'd':
printf("%f / %f = %f\n",a,b,a/b);
break;
default:
printf("program error!\n");
}
}
printf("bye!");
return 0;
}
char get_choice(void)
{
char ch;
printf("**********************************\n");
printf("Enter the operation of your choice\n");
printf("a. add s. subtract\n");
printf("m. multiply d. divide\n");
printf("q. quit\n");
printf("**********************************\n");
ch = get_first();
while( ch != 'a' && ch != 's' && ch != 'm' && ch != 'd' && ch != 'q')
{
printf("please respond a, s, m, d or q\n");
ch = get_first();
}
return ch;
}
char get_first(void)
{
char ch;
while( isspace(ch = getchar()) ) //选到第一个非空字符
continue;
while(getchar() != '\n') //去掉多余字符
continue;
return ch;
}
float get_float(char choice)
{
float input;
char ch;
while(scanf("%f",&input) != 1)
{
while((ch = getchar()) != '\n')
putchar(ch);
printf(" is not an num.\nplease enter an num value,such as 2, -178 or 3.5:");
}
if(choice == 'd' && input == 0 )
{
printf("Enter a number other than 0:");
input = get_float(choice); //重新调用这个函数,当里面返回了正确的值要记得接受再向上返回
}
return input;
}标签：count,char,ch,get,choice,第六版,Plus,printf,Primer 来源： https://blog.csdn.net/weixin_50166464/article/details/118875948