# Experiment one

2020-11-06 22:11:40

1. Abbreviated program , Output the following information ： **********￥￥ ￥￥￥ This is my first C program! **********￥￥￥￥￥

``````#include<stdlib.h>
int main(void)
{
printf("**********￥￥\n");/*wj*/
printf("￥￥￥\n");
printf("This i my first C program!\n");
printf("**********￥￥￥￥￥\n");
system("pause");
return 0;
}```
2. Enter the radius of the cylinder r  And high h, Calculate and output its volume .
```#include<stdio.h>
#include<stdlib.h>
#define PI 3.1415926
int main(void)
{
float r, h;
float v;

scanf("%f", &r);
printf(" Please enter the height of the cylinder h:");
scanf("%f", &h);
v = PI * r * r * h;
printf(" The volume of the cylinder v by ：%f", v);
system("pause");
return 0;
}```
3. Enter three numbers to variables a,b,c  in , Average them .
```#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
int main(void)
{
int a, b, c;/*number*/
float aver;

scanf("%d", &a);
scanf("%d", &b);
scanf("%d", &c);
aver = (a + b + c) / 3.0;
printf(" The average value is :%f", aver);
system("pause");
return 0;
}
4. Enter seconds , Press it by the hour . minute . Seconds to output . For example, the input 24680, The output 6  Hours 51
branch 20  second .

```#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
int main(void)
{
int s;
int hour, minute, second;/* Company  */

printf(" Please enter the number of seconds :");
scanf("%d", &s);
hour = s/3600;
minute = (s % 3600) / 60;
second = s % 60;
printf("%d The second is equal to %d Hours %d branch %d second ", s, hour, minute, second);
system("pause");
return 0;
}```
5.
(1) Write a program to calculate the volume of the sphere , Where the radius of the sphere is 10m（ Pay attention to the way the score is written ）
(2) Modify the procedure in the above question , Allows you to enter the radius of the sphere .
```#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#define PI 3.1415926
int main(void)
{
float v;/* Volume */
scanf("%f", &r);
v = 4.00/ 3.00* PI * r * r * r;
printf(" The volume of the sphere v by :%f", v);
system("pause");
return 0;
}```
6. Write a program , Use printf  Show the following graphics on the screen ：
``````

#define _CRT_SECURE_NO_WARNINGS #include<stdio.h> #include<stdlib.h> int main(void) { printf(" *\n"); printf(" *\n"); printf(" *\n"); printf(" * *\n"); printf(" * *\n"); printf(" *\n"); system("pause"); return 0; }``` 7. Write a program , Ask the user to enter a dollar variable , And then it shows an increase 5% The corresponding amount after the tax rate forehead , The format is as follows Enter an amount： 100.00 With tax added：\$105.00

``````int main(void)
{
float money;/* money */
float moneyWithTax;
printf("Enter an amount：");
scanf("%f", &money);
moneyWithTax = money * (1 + 0.05);
system("pause");
return 0;
}```

8.(1) Programming requires user input x  Value , Then display the values of the following polynomials ：
3x5+2x4-5x3-x2+7x-6
```#include<stdio.h>
#include<stdlib.h>
int main(void)
{
float x, y;/* Count */

printf(" Please enter x Value :");
scanf("%f", &x);
y = 3 * x * x * x * x * x + 2 * x * x * x * x - 5 * x * x * x - x * x + 7 * x - 6;
printf(" polynomial 3x5+2x4-5x3-x2+7x-6 The value of is :%f", y);
system("pause");
return 0;
}```
(2) Revise the question above , Use the following formula to evaluate polynomials
((((3x+2)x-5)x-1)x+7)x-6

```#include<stdio.h>
#include<stdlib.h>
int main(void)
{
float x, y;/* Count */
printf(" Please enter x Value :");
scanf("%f", &x);
y = ((((3 * x + 2) * x - 5) * x - 1) * x + 7) * x - 6;
printf(" polynomial ((((3x+2)x-5)x-1)x+7)x-6 The value of is :%f", y);
system("pause");
return 0;
}```
9. Write a program , Ask the user to enter a dollar amount , Then show how to use the least 20  dollar 、10
dollar 、5  The dollar and 1  Dollars to pay
Enter a dollar amount:93
\$20 bills:4
\$10 bills:1
\$5 bills:0
\$1 bills:3
( Tips ： Divide the payment amount by 20, determine 20  The amount of dollars , And then subtract... From the payment amount 20  The dollar
Total sum , Repeat for other denominations , Make sure you use integer values in your program , Don't use floating point numbers )

```#include<stdio.h>
#include<stdlib.h>
int main(void)
{
int money, twenty, ten, five, one;/*12345*/
printf("Enter a dollar amount:");
scanf_s("%d", &money);
twenty = money / 20;
money = money - twenty * 20;
ten = money / 10;
money = money - ten * 10;
five = money / 5;
money = money - 5 * five;
one = money;
printf("\$20 bills:%d\n", twenty);
printf("\$10 bills:%d\n", ten);
printf("\$5 bills:%d\n", five);
printf("\$1 bills:%d\n", one);
system("pause");
return 0;
}```

``````