/*. Write a program to add two integers using functions.*/

#include <stdio.h> // FUNCTION DECLARATIONint sum(int , int );int main(){int num1, num2;printf("\n Enter the first number: ");scanf("%d", &num1);printf("\n Enter the second number: ");scanf("%d", &num2);// FUNCTION CALLprintf("\n Total = %d", sum(num1, num2));return 0;} // FUNCTION DEFINITIONint sum (int a, int b) // FUNCTION HEADER{ // FUNCTION BODYreturn( a + b);}

/*. Write a program to find biggest of three integers using functions.*/

#include <stdio.h>int greater(int , int , int );int main(){int num1, num2, num3, large;printf("\n Enter the first number: ");scanf("%d", &num1);printf("\n Enter the second number: ");scanf("%d", &num2);printf("\n Enter the third number: ");scanf("%d", &num3);large = greater(num1, num2, num3);printf("\n Largest number = %d", large);return 0;}int greater(int a, int b, int c){if(a>b && a>c)return a;if(b>a && b>c)return b;elsereturn c;}/*. Write a program to calculate area of a circle using function.*/

#include <stdio.h>

float cal_area(float );int main(){float area, radius;printf("\n Enter the radius of the circle: ");scanf("%f", &radius);

printf("\n Area of the circle with radius %.2f = %.2f", radius, cal_area(radius));return 0;}float cal_area(float radius){return (3.14 * radius * radius);}/*. Write a program, using functions, to fi nd whether a number is even or odd.*/

#include <stdio.h>int evenodd(int);int main(){int num, flag;printf("\n Enter the number: ");scanf("%d", &num);flag = evenodd(num);if (flag == 1)printf("\n %d is EVEN", num);elseprintf("\n %d is ODD", num);return 0;}int evenodd(int a){return(a%2==0 ?1:0);}/*. Write a program to convert time to minutes.*/

#include <stdio.h>#include <conio.h>int myfunc(int , int );main(){int hrs, minutes;printf("\n Enter hours and minutes: ");scanf("%d %d", &hrs, &minutes);

printf("\n Total minutes = %d", myfunc(hrs, minutes));getch();return 0;}int myfunc(int hrs, int minutes){

return(hrs*60 + minutes);}/*If the lengths of the sides of a triangle are denoted by a, b, and c, then area of triangle is given byrootover ( S * (S-a) * (S-b) * (S-c))where, S = ( a + b + c ) / 2

*/

float func(int,int,int,int);#include<stdio.h>#include<math.h>main() {

int s1,s2,s3,s;int area;

printf("enter 3 sides of triangle: \n\n");scanf("%d%d%d",&s1,&s2,&s3);

s=s1+s2+s3/2;

printf("\narea = %d",func(s1,s2,s3,s));}

float func(int i, int j, int k, int h) {return (sqrt(h*((h-i)*(h-j)*(h-k))));}//Write a function to calculate the factorial value //of any integer entered through the keyboard.

#include<stdio.h>#include<conio.h>

void func();main() {int num;printf("Please enter any number: ");scanf("%d",&num);func(num);}

void func(int n) {int fact=1;for(;n>=1;n--) {fact=fact*n;}

printf("\n\nFactorial value = %d \n",fact);}

/*Write a function to find the binary equivalent of a given decimal integer and display it.*/

int binary();

#include<stdio.h>main() {int num;printf("\t\tDecimal Integer to Binary conversion\n\n\n");printf("Enter the number: ");scanf("%d",&num);binary(num);}

int binary(int n) {while(n!=0) {printf("%d",n%2);n=n/2;}}Examples on recursion

#include<stdio.h> int factorial(int n); int main() { int n; printf("Enter a positive integer: "); scanf("%d",&n); printf("Factorial of %d = %ld", n, factorial(n)); return 0; } int factorial(int n) { if(n!=1) return n*factorial(n-1); }

/* calculate power of a number using recursion*/

#include <stdio.h> long power (int, int);

int main(){ int pow, num; long result; printf("Enter a number: "); scanf("%d", &num); printf("Enter it's power: "); scanf("%d", &pow); power(num, pow); printf("%d^%d is %ld", num, pow, power(num, pow)); return 0;} long power (int num, int pow){ if (pow!=0) { return (num * power(num, pow - 1)); } return 1;}/* sum of digits using recursion*/#include <stdio.h> int sum (int a); int main(){ int num, result; printf("Enter the number: "); scanf("%d", &num); result = sum(num); printf("Sum of digits in %d is %d\n", num, result); return 0;} int sum (int num){ if (num != 0) { return (num % 10 + sum (num / 10)); } else { return 0; }}#include <stdio.h>

int sum (int ); int main(){ int num, result; printf("Enter the number: "); scanf("%d", &num); sum(num); printf("Sum of digits in %d is %d\n", num, sum(num)); return 0;} int sum (int num){ if (num != 0) { return (num % 10 + sum (num / 10)); } else { return 0; }}