admin 管理员组

文章数量: 1086864

2章编程题

2.1

编写一个程序,使用printf在屏幕上显示下面的图形:

#include <stdio.h>int main(void) {printf("       *\n");printf("      * \n");printf("     *  \n");printf("*   *   \n");printf(" * *    \n");printf("  *     \n");return 0;
}

 2.2

        编写一个计算球体体积的程序,其中球体半径为10 m,参考公式v = 4/3r 3 。注意,分数4/3应写为4.0f/3.0f。(如果分数写成4/3会产生什么结果?)提示:C语言没有指数运算符,所以需要对r自乘两次来计算r 3 。

#include <stdio.h>int main(void) {printf("Sphere volume: %.2f cubic meters\n", 4.0f/3.0f * 3.14f * 1000);return 0;
}

2.3

         修改上题中的程序,使用户可以自行录入球体的半径。

#include <stdio.h>int main(void) {int r = 0;printf("Enter radius: ");scanf("%d", &r);printf("\nSphere volume: %.2f cubic meters\n",4.0f/3.0f * 3.14f * r * r * r);return 0;
}

2.4 

        编写一个程序,要求用户输入一个美元数量,然后显示出增加5%税率后的相应金额。格式如下所示:
Enter an amount: 100.00
With tax added: $105.00

#include <stdio.h>int main(void) {float money = 0.0f;printf("Enter an amount: ");scanf("%f", &money);printf("With tax added: $%.2f\n", money * 1.05f);return 0;
}

2.5

        编程要求用户输入x的值,然后显示如下多项式的值:
提示:C语言没有指数运算符,所以需要对x进行自乘来计算其幂。(例如,x*x*x就是x的三次方。)

#include <stdio.h>int main(void) {int x = 0;printf("Enter value for x: ");scanf("%d", &x);printf("Result: %d\n",(3 * x * x * x * x * x) + (2 * x * x * x * x) - (5 * x * x * x)- (x * x) + (7 * x) - 6);return 0;
}

2.6

        修改上题,用如下公式对多项式求值:

((((3x + 2) x - 5)x - 1)x + 7)x - 6
注意,修改后的程序所需的乘法次数减少了。这种多项式求值方法即Horner法则(Horner’s Rule)。

#include <stdio.h>int main(void) {int x = 0;printf("Enter value for x: ");scanf("%d", &x);printf("Result: %d\n",((((3 * x + 2) * x - 5) * x - 1) * x + 7) * x - 6);return 0;
}

2.7        

        编写一个程序,要求用户输入一个美金数量,然后显示出如何用最少的20美元、10美元、5美元和1
美元来付款:
Enter a dollar amount: 93
$20 bills: 4
$10 bills: 1
$5 bills: 0
$1 bills: 3
提示:将付款金额除以20,确定20美元的数量,然后从付款金额中减去20美元的总金额。对其他面值的钞票重复这一操作。确保在程序中始终使用整数值,不要用浮点数。

#include <stdio.h>int main(void) {int money = 0;printf("Enter a dollar amount: ");scanf("%d", &money);printf("$20 bills: %d\n", money/20);money -= 20 * (money/20);printf("$10 bills: %d\n", money/10);money -= 10 * (money/10);printf(" $5 bills: %d\n", money/5);money -= 5 * (money/5);printf(" $1 bills: %d\n", money);return 0;
}

2.8

        编程计算第一、第二、第三个月还贷后剩余的贷款金额:
Enter amount of loan: 20000.00
Enter interest rate: 6.0
Enter monthly payment: 386.66
Balance remaining after first payment: $19713.34
Balance remaining after second payment: $19425.25
Balance remaining after third payment: $19135.71
在显示每次还款后的余额时保留两位小数。提示:每个月的贷款余额减去还款金额后,还需要加上贷款余额与月利率的乘积。月利率的计算方法是把用户输入的利率转换成百分数再除以12。

#include <stdio.h>int main(void) {float loan = 0.0f,rate = 0.0f,payment = 0.0f;printf("Enter amount of loan: ");scanf("%f", &loan);printf("Enter interest rate: ");scanf("%f", &rate);printf("Enter monthly payment: ");scanf("%f", &payment);loan = loan - payment + (loan * rate / 100.0 / 12.0);printf("Balance remaining after first payment: $%.2f\n", loan);loan = loan - payment + (loan * rate / 100.0 / 12.0);printf("Balance remaining after second payment: $%.2f\n", loan); loan = loan - payment + (loan * rate / 100.0 / 12.0);printf("Balance remaining after third payment: $%.2f\n", loan);return 0;
}

本文标签: 2章编程题