Function and Pointers Programs

 C Program to swap the values of two variables.
```#include<stdio.h>
void swap(int, int);  //prototype
int main( ){
int x,y;
printf("Enter X: ");
scanf("%d",&x);
printf("Enter Y: ");
scanf("%d",&y);
printf("BEFORE SWAP:\n");
printf("X=%d and Y=%d",x,y);
swap(x,y);   //calling
return 0;
}
//definition
void swap(int x, int y){
int temp = x;
x = y;
y = temp;
printf("AFTER SWAP : \n");
printf("X=%d and Y=%d",x,y);
}```
OUTPUT :
```Enter X: 15
Enter Y: 28

BEFORE SWAP:
X=15 and Y=28

AFTER SWAP:
X=28 and Y=15```
 C Program to Calculate Factorial of a given Number.
```#include<stdio.h>
int fact(int);

int main(){
int n,res;
printf("Enter number: ");
scanf("%d",&n);
res = fact(n);
printf("Factorial : %d",res);
return 0;
}

int fact(int x){
int i, f=1;
for(i=1; i<=x; i++){
f = f*i;
}
return f;
}```
OUTPUT :
```Enter a Number : 5
Factorial = 120```
 C Program to find out ncr factor by using a user defined function for factorial.  FORMULA : ncr = n! / ((n-r)! * r!)
```#include<<stdio.h>
int fact(int);

int main(){
int n,r, res;
printf("Enter n: ");
scanf("%d",&n);
printf("Enter r: ");
scanf("%d",&r);
res = fact(n)/(fact(n-r)*fact(r));
printf("Result nCr Is: %d",res);
}

int fact(int x){
int i, f=1;
for(i=1; i<=x; i++){
f = f*i;
}
return f;
}```
OUTPUT :
```Enter n: 5
Enter r: 3
Result nCr Is : 10```
 C Program to Calculate Factorial of a given Number using Recursion.
```#include<stdio.h>
int fact(int);

int main(){
int n,res;
printf("Enter number: ");
scanf("%d",&n);
res = fact(n);
printf("Factorial : %d",res);
return 0;
}

int fact(int x){
if(x==0 || x==1){
return 1;
}
else{
return x*fact(x-1);
}```
OUTPUT :
```Enter a Number : 5
Factorial = 120```
 C Program to Calculate HCF and LCM of two Number
```#include<stdio.h>
int lcm(int , int);
int hcf(int , int);
int main( ) {
int a,b;
printf("Enter two Number : ");
scanf("%d%d",&a,&b);
int lc=lcm(a,b);
int hc =(a>b)?hcf(a,b):hcf(b,a);
printf("LCM = %d\n",lc);
printf("HCF = %d\n",hc);
return 0;
}
int lcm(int a, int b) {
int res = a*b/hcf(a,b);
return res;
}
int hcf(int a, int b) {
int rem;
while( low != 0) {
rem = a%b;
a = b;
b = rem;
}
return gre;
}```
OUTPUT :
```Enter two Number : 15 50
LCM = 150
HCF = 5```
 C Program to calculate 1!+2!+3!+4!+5!.
```#include<stdio.h>
int fact(int);
int main( ){
int i, sum=0;
for(i=1; i<=7; i++){
sum = sum+fact(i);
}
printf("SUM = %d",sum);
return 0;
}
int fact(int x){
if(x==0 || x==1){
return 1;
}
else{
return x*fact(x-1);
}```
OUTPUT :
`SUM = 153`

 C Program to calculate 1/1!+2/2!+3^2/3!+4^3/4!+5^4/5!+6^5/6!
```#include<stdio.h>
int fact(int);
float power(int,int);
int main( ){
int i;
float sum;
for(i=0; i<=6; i++){
sum = sum+power(i,i-1)/fact(i);
}
printf("Sum = %f\n",sum);

return 0;

}

int fact(int x){
if(x==0 || x==1){
return 1;
}
else{
return x*fact(x-1);
}
}
float power(int x, int y){
int j, result=1;
for(j=1; j<=y; j++){
result = x*result;
}
return result;
}```
OUTPUT :
`Sum = 22.174999`
 C Program to compute the cosine series using function. =1-x2/2!+x4/4!-x6/6!----
```#include<stdio.h>
#include< math.h >
float cal_cos(int, int);
int fact(int);
int main( )
{

int x, n;
printf("Enter the value of x : ");
scanf("%d",&x);
printf("Enter the value of n : ");
scanf("%d",&n);
float r = cal_cos(x, n);
printf("Result = %f ",r);
return 0;
}
float cal_cos(int a, int n) {
int j =2 ;
float sum = 1;
for(i=1; i<=n; i++)
{
if(i%2 ==0)
{
sum = sum+pow(a,j)/(float)fact(j);
}
else
{
sum = sum-pow(a,j)/fact(j);
}
}
return sum;
}

int fact(int x){
int i, f=1;
for(i=1; i<=x; i++){
f = f*i;
}
return f;
}```
OUTPUT :
```Enter the Value of x : 3
Enter the Value of n : 3
Result = -1.250000```
 C Program to calculate sum of two number using Pointer
```#include<stdio.h>
int main( ) {
int a, b, *p, *q, sum;
printf("Enter two number : ");
scanf("%d%d", &a, &b);
p = &a;
q = &b;
sum = *p + *q;
printf("SUM = %d\n",sum);
return 0;
}```
OUTPUT :
```Enter two number : 10 20
SUM = 30```
 C Program to swap two Number using Pointer
```#include<stdio.h >
int main( ) {
int x, y, *a, *b, temp;
printf("Enter the value of X and Y : ");
scanf("%d%d", &x, &y);
printf("Before Swapping\nX = %d\nY = %d\n", x, y);
a = &x;
b = &y;
temp = *b;
*b = *a;
*a = temp;
printf("After Swapping\nX = %d\nY = %d\n", x, y);
return 0;
}```
OUTPUT :
```Enter the value of X and Y : 10 20
Before Swapping
X = 10
Y = 20
After Swapping
X = 20
Y = 10```
 C Program to find the length of String using Pointer
```#include<stdio.h>
int main( ) {
char str[20];
int length = 0;
printf("\nEnter any String : ");
gets(str);
char* p = str;
while (*p != '\0') {
length++;
p++;
}
printf("Length of  %s is : %d", str, length);
return 0;
}```
OUTPUT :
```Enter any String : prowess
Length of prowess is : 7```
 C Program to Access Array Elements Using Pointer
```#include<stdio.h>
int main( ) {
int arr[5], i;
printf("Enter Elements of Array:");
for(i=0;i<5;i++){
scanf("%d",arr+i);
}
printf("You have entered : ");
for(i=0;i<5;i++){
printf("%d ",*(arr+i));
}
return 0;
}```
OUTPUT :
```Enter Elements of Array : 1 4 6 7 8
You have entered : 1 4 6 7 8```
 C Program to convert binary to decimal number using user define function.
```#include<stdio.h>
#include<math.h>
long binToDec(long n);
int main() {
long bi;
printf("Enter a binary no. :");
scanf("%ld", &bi);
printf("BINARY : %ld \n",bi);
printf("DECIMAL: %ld",binToDec(bi));
return 0;
}

long binToDec(long n) {
int rem;
long dec = 0, i=0;
while(n != 0) {
remainder = n%10;
n = n/10;
dec = dec + (rem*pow(2,i));
++i;
}
return dec;
}```
OUTPUT :
```Enter a binary no. :11011
BINARY  : 11001
DECIMAL : 27```
 C Program to convert decimal to binary number using user define function.
```#include<stdio.h>
#include<math.h>
long decToBin(long n);
int main() {
long n;
printf("Enter a decimal no. :");
scanf("%ld", &n);
printf("DECIMAL: %ld", n);
printf("BINARY : %ld",decToBin(n));
return 0;
}

long decToBin(long n) {
int rem;
long binary = 0, i = 1;
while(n != 0) {
rem = n%2;
n = n/2;
binary= binary + (rem*i);
i = i*10;
}
return binary;
}```
OUTPUT :
```Enter a decimal no. : 27
DECIMAL : 27
BINARY  : 11001```
 C Program to reverse of a number using recursion.
```#include<stdio.h>
#include<math.h>
int rev(int, int);
int main() {
int num, res;
int length = 0, temp;
printf("Enter a number: ");
scanf("%d", &num);
temp = num;
while (temp != 0) {
length++;
temp = temp / 10;
}
res = rev(num, length);
printf("Reverse = %d\n",res);
return 0;
}

int rev(int n, int len) {
int x;
if (len == 1) {
return n;
}
else {
x = ((n % 10) * pow(10, len-1));
return ( x + rev(n / 10, --len));
}
}```
OUTPUT :
```Enter a number: 1234
Reverse = 4321```

#### CONTACT DETAILS

info@prowessapps.in
(8AM to 10PM):

+91-9026070669 , +91-9451396824