Input-Output Exercises

Exercise 1

Write a C program that convert a temperature from Centigrade to Fahrenheit.

The centigrade scale, which is also called the Celsius scale, was developed by Swedish astronomer Andres Celsius. In the centigrade scale, water freezes at 0 degrees and boils at 100 degrees. The centigrade to Fahrenheit conversion formula is:

C = (5/9) * (F - 32)

where F is the Fahrenheit temperature. 

Sample Solution

C Code:

#include<stdio.h>
float temp_f; /* degrees fahrenheit */
float temp_c; /* degrees centigrade */
char line_text[50]; /* a line of input
 */

int main(){
 printf("Input a temperature (in Centigrade): ");
 fgets(line_text,sizeof(line_text), stdin);
 sscanf(line_text,"%f",&temp_c);

 temp_f
 =((9.0/5.0)* temp_c)+32.0;
 printf("%f degrees Fahrenheit.\n", temp_f);

 return(0);
}

Sample Output:

Input a temperature (in Centigrade): 45 
113.000000 degrees Fahrenheit.

Flowchart

---

Exercise 2

Write a C program that calculates the volume of a sphere.

A sphere is a perfectly round geometrical object in three-dimensional space that is the surface of a completely round ball.

In three dimensions, the volume inside a sphere is derived to be V = 4/3*π*r3 where r is the radius of the sphere

Sample Solution

C Code:

#include<stdio.h>
float myradius; /* radius of the sphere */
float myvolume; /* volume of the sphere (to be computed)
 */
char line_text[50]; /* a line from the keyboard */

/* the value of pi to 50 places, from wikipedia */
constfloat PI =3.14159265358979323846264338327950288419716939937510;

int main(){

 printf("Input the radius of the sphere : ");
 fgets(line_text,sizeof(line_text), stdin);
 sscanf(line_text,"%f",&myradius);

 myvolume =(4.0/3.0)* PI *(myradius
 * myradius * myradius);/* volumn=(4/3) * pi * r^3*/
 printf("The volume of sphere is %f.\n", myvolume);

 return(0);
}

Sample Output:

Input the radius of the sphere: 2.56 
The volume of sphere is 70.276237.

Flowchart

---

Exercise 3

Write a C program that prints the perimeter of a rectangle to take its height and width as input.

Pictorial Presentation:

Sample Solution

C Code:

#include<stdio.h>
int main(){
float rec_width; /* width of the rectangle */
float rec_height; /* height of the rectangle
 */
float rec_perimeter; /* perimeter (to be computed) */

 printf("Input the height of the Rectangle : ");
 sscanf(line_text,"%f",&rec_height);
 printf("Input
 the width of the Rectangle : ");
 sscanf(line_text,"%f",&rec_width);
 rec_perimeter =2.0*(rec_height + rec_width);/* perimeter = 2 * ( width + height )*/
 printf("Perimeter
 of the Rectangle is : %f\n", rec_perimeter);
 return0;
}

Sample Output:

Input the height of the Rectangle: 5 
Input the width of the Rectangle: 7 
Perimeter of the Rectangle is: 24.000000

Flowchart

---

Exercise 4

Write a C program that converts kilometers per hour to miles per hour.

Pictorial Presentation:

Sample Solution

C Code:

#include<stdio.h>
float kmph; /* kilometers per hour */
float miph;
 /* miles per hour (to be computed) */
char line_text[50]; /* a line from the keyboard */

int main()
{
 printf("Input kilometers per hour: ");
 fgets(line_text,
 sizeof(line_text), stdin);
 sscanf(line_text,"%f",&kmph);

 miph =(kmph *0.6213712);
 printf("%f miles per hour\n", miph);

 return(0);
}

Sample Output:

Input kilometers per hour: 15 
9.320568 miles per hour

Flowchart

---

Exercise 5

Write a C program that takes hours and minutes as input, and calculates the total number of minutes.

Pictorial Presentation:

Sample Solution

C Code:

#include<stdio.h>
int hrs; /* given number of hours */
int mins; /* given number of minutes */
int tot_mins;
 /* total number of minutes (to be computed) */

constintMINaHOUR=60; /* number of minutes in an hour */

char line_text[50]; /* line of input from keyboard */

int
 main(){
 printf("Input hours: ");
 fgets(line_text,sizeof(line_text), stdin);
 sscanf(line_text,"%d",&hrs);

 printf("Input minutes: ");

 fgets(line_text,sizeof(line_text), stdin);
 sscanf(line_text,"%d",&mins);

 tot_mins = mins +(hrs *MINaHOUR);

 printf("Total: %d minutes.\n", tot_mins);


 return(0);
}

Sample Output:

Input hours: 5 
Input minutes: 37 
Total: 337 minutes.

Flowchart

---

Exercise 6

Write a program in C that takes minutes as input, and display the total number of hours and minutes.

Pictorial Presentation:

Sample Solution

C Code:

#include<stdio.h>
int tot_mins;/* given number of minutes */
int hrs; /* number of hours (to be computed) */
int mins;
 /* number of minutes (to be computed) */

constintMINaHOUR=60; /* number of minutes in an hour */

char line_text[50]; /* line of input from keyboard */

int
 main(){
 printf("Input minutes: ");
 fgets(line_text,sizeof(line_text), stdin);
 sscanf(line_text,"%d",&tot_mins);

 hrs =(tot_mins /MINaHOUR);

 mins =(tot_mins %MINaHOUR);

 printf("%d Hours, %d Minutes.\n", hrs, mins);

 return(0);
}

Sample Output:

Input minutes: 546 
9 Hours, 6 Minutes.

Flowchart

---

Exercise 7

Write a program in C that reads a firstname, lastname and year of birth and display the names and the year one after another sequentially.

Pictorial Presentation:

Sample Solution

C Code:

#include<stdio.h>
int main()
{
 char firstname[20], lastname[20];
 int bir_year;
 printf("Input your firstname: ");
 scanf("%s", firstname);

 printf("Input your lastname: ");
 scanf("%s", lastname);
 printf("Input your year of birth: ");
 scanf("%d",&bir_year);
 printf("%s %s %d\n", firstname,
 lastname, bir_year);
 return0;
}

Sample Output:

Input your firstname: Tom 
Input your lastname: Davis 
Input your year of birth: 1982 
Tom Davis 1982

Flowchart

---

Exercise 8

Write a program in C to calculate the sum of three numbers with getting input in one line separated by a comma.

Pictorial Presentation:

Sample Solution

C Code:

#include<stdio.h>
int num1,num2,num3; /* declaration of three variables */
int sum;
char line_text[50]; /* line of input from keyboard
 */

int main()
{
 printf("Input three numbers separated by comma: ");
 fgets(line_text,sizeof(line_text), stdin);
 sscanf(line_text,"%d, %d, %d",&num1,
 &num2,&num3);
 sum = num1+num2+num3;
 printf("The sum of three numbers: %d\n", sum);
 return(0);
}

Sample Output:

Input three numbers separated by comma: 5,10,15 
The sum of three numbers: 30

Flowchart

---

Exercise 9

Write a C program to perform addition, subtraction, multiplication and division of two numbers.

Pictorial Presentation:

Sample Solution

C Code:

#include<stdio.h>
int main()
{
 int num1, num2;
 int sum,sub, mult, mod;
 float div;


 /* 
 * Read two numbers from user separated by comma 
 */
 printf("Input any two numbers separated by comma: ");
 scanf("%d,%d",
 &num1,&num2);

 /* 
 * Performs all arithmetic operations 
 */
 sum = num1 + num2;

 sub= num1 - num2;
 mult = num1 * num2;
 div =(float)num1 / num2;
 mod = num1 % num2;

 /* 

 * Prints the result of all arithmetic operations 
 */
 printf("The sum of the given numbers: %d\n", sum);
 printf("The difference of the given numbers: %d\n",
 sub);
 printf("The product of the given numbers: %d\n", mult);
 printf("The quotient of the given numbers: %f\n", div);
 printf("MODULUS = %d\n", mod);

 
 return0;
}

Sample Output:

Input any two numbers separated by comma: 10,5 
The sum of the given numbers: 15 
The difference of the given numbers: 5 
The product of the given numbers: 50 
The quotient of the given numbers: 2.000000
MODULUS = 0

Flowchart

---

Exercise 10

Write a C program to find the third angle of a triangle if two angles are given.

Pictorial Presentation:

Sample Solution

C Code:

#include<stdio.h>
int main()
{
 int ang1, ang2, ang3;/*are three angles of a triangle */

 /* Read two angles of the triangle from user separated
 by comma*/
 printf("Input two angles of triangle separated by comma : ");
 scanf("%d, %d",&ang1,&ang2);

 ang3 =180-(ang1 + ang2);
 /* Calculates the third angle */

 printf("Third angle of the triangle : %d\n", ang3);

 return0;
}

Sample Output:

Input two angles of triangle separated by comma : 50,70 
Third angle of the triangle : 60 

Flowchart