《c primer plus》编程练习回顾-第七章

#include<stdio.h>
int main(void)
{
int space = 0, new_line = 0, others = 0;
char ch;
while ((ch = getchar())!='#')
{
if (ch == ' ')
space++;
else if (ch == '\n')
new_line++;
else others++;
}
printf("space=%d,new_line=%d,others=%d\n", space, new_line, others);
return 0;

}

#include<stdio.h>
int main(void)
{
char ch;
int count = 0;
while ((ch = getchar()) != '#')
{
count++;
printf("%c %d  ", ch, ch);
if (count % 8 == 0)
printf("\n");
}
return 0;
}

#include<stdio.h>
int main(void)
{
int i_even = 0, sum_even = 0, i_odd = 0, sum_odd = 0, num;
printf("Please input numbers (0 to quit):");
/*用恒成立的循环持续获取输入*/
while (1)
{
scanf("%d", &num);
if (num == 0) break;
if (num % 2 == 0) { i_even++; sum_even += num; }
else { i_odd++; sum_odd += num; }
}
printf("even number's count: %d\n", i_even);
printf("even number's sum : %d\n", sum_even);
printf("odd number's count: %d\n", i_odd);
printf("odd number's sum : %d\n", sum_odd);
return 0;
}

#include<stdio.h>
int main(void)
{
int a = 0, b = 0;
char ch;
printf("Please input a string end by #:");
while ((ch = getchar()) != '#')
{
if (ch == '.')
{

putchar('!');
a++;
}
else if (ch == '!')
{
putchar('!');
putchar('!');
b++;
}
else putchar(ch);
}
printf("\nthe times of '.' replaced by '!': %d\n", a);
printf("the times of '!' replaced by '!!': %d\n", b);
return 0;
}

#include<stdio.h>
int main(void)
{
int num, odds = 0, even = 0;
while (scanf("%d", &num) == 1 && num != 0)
{
switch (num % 2)
{
case 0:odds++; break;
case 1:even++; break;
}
}
printf("odds=%d,even=%d", odds, even);
return 0;
}

#include<stdio.h>
int main(void)
{
int num = 0;
char ch1, ch2 = 'a';
while (scanf("%c", &ch1) == 1 && ch1 != '#')
{
if (ch1 == 'i'&&ch2 == 'e')
num++;
else
ch2 = ch1;
}
printf("%d\n", num);
return 0;
}

#include<stdio.h>
#define BASIC 10.00
#define TIME 40
#define ADD 1.5
#define LIMIT1 300
#define RATE1 0.15
#define LIMIT2 150
#define RATE2 0.20
#define RATE3 0.25
int main(void){
double hours, gross, tax;
printf("input the work hours of a week:");
scanf("%lf", &hours);
if (hours > 40) hours = 40 + (hours - 40) * 1.5;
gross = hours * BASIC;
printf("gross income:\t\t%lf\n", gross);
if (gross <= LIMIT1) tax = gross * RATE1;
else if (gross <= LIMIT2) tax = LIMIT1 * RATE1 + (gross - LIMIT1) * RATE2;
else tax = LIMIT1 * RATE1 + LIMIT2 * RATE2 + (gross - LIMIT1 - LIMIT2) * RATE3;
printf("tax:\t\t\t%lf\n", tax);
printf("net income:\t\t%lf\n", gross - tax);
return 0;
}

#include<stdio.h>
int get_int(void);
#define TIME 40
#define ADD 1.5
#define LIMIT1 300
#define RATE1 0.15
#define LIMIT2 150
#define RATE2 0.20
#define RATE3 0.25
int main(void){
double basic, hours, gross, tax;
printf("Enter the number corresponding to the desired pay rate or action:\n");
printf("1) $8.75/hr\t\t\t2) $9.33/hr\n");
printf("3) $10.00/hr\t\t\t4) $11.20/hr\n");
printf("5) quit\n");
switch (get_int())
{
case 1: basic = 8.75; break;
case 2: basic = 9.33; break;
case 3: basic = 10.00; break;
case 4: basic = 11.20; break;
default: printf("quit\n"); return 0;
}
printf("you have select $%.2lf\n", basic);
printf("input the work hours of a week:");
scanf("%lf", &hours);
if (hours > 40) hours = 40 + (hours - 40) * 1.5;
gross = hours * basic;
printf("gross income:\t\t%lf\n", gross);
if (gross <= LIMIT1) tax = gross * RATE1;
else if (gross <= LIMIT2) tax = LIMIT1 * RATE1 + (gross - LIMIT1) * RATE2;
else tax = LIMIT1 * RATE1 + LIMIT2 * RATE2 + (gross - LIMIT1 - LIMIT2) * RATE3;
printf("tax:\t\t\t%lf\n", tax);
printf("net income:\t\t%lf\n", gross - tax);
return 0;
}
int get_int(void)
{
int num;
char str[40];
while (scanf("%d", &num) != 1)
{
gets(str);
printf("error! %s is not a number. input again.\n", str);
}
while (getchar() != '\n');
return num;
}

#include<stdio.h>
int isprime(int);
int main(void)
{
int num, i;
printf("input a positive number:");
scanf("%d", &num);
printf("all the primes <= %d:\n", num);
for (i = 2; i <= num; i++)
if (isprime(i))
printf("%d\t", i);
printf("\n");
return 0;
}
int isprime(int n)
{
int div;
for (div = 2; div * div <= n; div++)
if (n % div == 0)
return 0;
return 1;
}

#include<stdio.h>
#define SINGLE 17850
#define HOST 23900
#define MARRIED_SHARE 29750
#define MARRIED_DIVORCE 14875
#define RATE1 0.15
#define RATE2 0.28
int main(void)
{
double type, pay, tax;
char ch;
while (1)
{
printf("Select the type of marriage:\n");
printf("1)SINGLE\n2)HOST\n3)MARRIED_SHARE\n4)MARRIED_DIVORCE\n5)quit\n");
while ((ch = getchar()) == '\n') continue;
switch (ch)
{
case '1': type = SINGLE; break;
case '2': type = HOST; break;
case '3': type = MARRIED_SHARE; break;
case '4': type = MARRIED_DIVORCE; break;
case '5': printf("quit\n"); return 0;
default: printf("input error\n"); continue;
}
printf("you have select %c\n", ch);
printf("input the pay:");
scanf("%lf", &pay);
if (pay <= type) tax = pay * RATE1;
else tax = type * RATE1 + (pay - type) * RATE2;
printf("wax is %.2lf\n", tax);
}
return 0;
}

#include <stdio.h>
#include <ctype.h>
#define ARTICHOKE 1.25
#define BEET 0.65
#define CARROT 0.89
#define DISCOUNT_LIMIT 100
#define DISCOUNT_RATE 0.05
#define FREIGHT_FEE1 3.50
#define FREIGHT_LIMIT1 5
#define FREIGHT_FEE2 10.00
#define FREIGHT_LIMIT2 20
#define FREIGHT_FEE3 8
#define FREIGHT_RATE 0.1
int main(void)
{
char ch;
double artichoke = 0, beet = 0, carrot = 0;
double sum, discount, freight;
printf("Please select your vegetable: a,b,c,q\n");
printf("a.artichoke price:$%.2f\n", ARTICHOKE);
printf("b.beet price:$%.2f\n", BEET);
printf("c.carrot price:$%.2f\n", CARROT);
printf("q.end\n");
printf("(price as dollars per pound)\n");
while ((ch = tolower(getchar())) != 'q')
{
switch (ch)
{
case 'a': printf("How many pounds of artichokes do you want?");
scanf("%lf", &artichoke);
printf("Please select your vegetable: a,b,c,q:");
continue;
case 'b': printf("How many pounds of beets do you want?");
scanf("%lf", &beet);
printf("Please select your vegetable: a,b,c,q:");
continue;
case 'c': printf("How many pounds of carrots do you want?");
scanf("%lf", &carrot);
printf("Please select your vegetable: a,b,c,q:");
continue;
default: break;
}
}
printf("%10s%10s%10s%10s\n", " ", "artichoke", "beet", "carrot");
printf("%10s%10.2lf%10.2lf%10.2lf\n", "price", ARTICHOKE, BEET, CARROT);
printf("%10s%10.2lf%10.2lf%10.2lf\n", "pound", artichoke, beet, carrot);
printf("%10s%10.2lf%10.2lf%10.2lf\n", "charge", ARTICHOKE * artichoke, BEET * beet, CARROT
* carrot);
sum = ARTICHOKE * artichoke + BEET * beet + CARROT * carrot;
if (sum > DISCOUNT_LIMIT) discount = sum*DISCOUNT_RATE;
else discount = 0;
printf("discount: %.2f\n", discount);
if (artichoke + beet + carrot <= 5) freight = 3.50;
else if (artichoke + beet + carrot <20) freight = 10;
else freight = 8 + (artichoke + beet + carrot) * 0.1;
printf("freight: %.2f\n", freight);
sum = sum - discount + freight;
printf("sum: %.2f\n", sum);
return 0;
}