Program:

#include<iostream>;
#define MAX 6
using namespace std;

int main()
{
    int a[MAX] = {10,20,30,40,50};
    int N = 5; //no. of elements
    int k = 2; //index position to insert data
    int item = 100; //item to be inserted in index position

    for(int i = N-1; i &gt;= k; i--){
        a[i+1] = a[i];
    }
    a[k] = item;

    for(int j = 0; j &lt; MAX; j++){
        cout &lt;&lt; a[j] &lt;&lt; "\t";
    }
}

Output:

10 20 100 30 40 50

Program:

#include<stdio.h>
int swap(int *a, int *b)
{
    int temp;
    temp = *a;
    *a = *b;
    *b = temp;
}
int main(){
    int x = 20, y = 50;
    printf("Before Swap: x= %d y= %d", x, y);
    swap(&x, &y);
    printf("\nAfter Swap: x= %d y= %d\n", x, y);
}

Output:

Before Swap: x = 20  y = 50 
After Swap:  x = 50  y = 20 

Program:

#include<stdio.h>
int fibo(int n){
    int f;
    if(n == 1 || n == 0) return n;
    f = fibo(n-1) + fibo(n-2);
    return f;
}
int main()
{
    int k,x;
    printf("Enter a number: ");
    scanf("%d",&x);
    k = fibo(x);
    printf("The %d number in fibonacci series is: %d\n",x,k);
    return 0;
}

Output:

Enter a number: 6
The 6 number in fibonacci series is: 8

Program:

#include<stdio.h>
int fact(int n){
    int f;
    if(n == 1) return 1;
    f = n * fact (n-1);
    return f;
}
int main()
{
    int k,x;
    printf("Enter a number: ");
    scanf("%d",&x);
    k = fact(x);
    printf("Factorial of %d is: %d\n",x,k);
    return 0;
}

Output:

Enter a number: 5
Factorial of 5 is: 120

Program:

#include<stdio.h>
int getPower(int base,int exponent)
{
    if(exponent == 0) return 1;
    return base * getPower(base,exponent-1);
}
int main()
{
    int base, exponent,z;
    printf("Enter base and exponent: ");
    scanf("%d %d", &base, &exponent);
    z = getPower(base,exponent);
    printf("Result = %d",z);
}

Output:

Enter base and exponent: 2 5
Result = 32

Program:

#include<stdio.h>
int main(){
    int i,rows,k=0,space;
    printf("Enter the no. of rows:");
    scanf("%d",&rows);
    for(i=1; i<=rows; ++i){
        for(space=1;space<=rows-i;++space){
                printf(" ");
            }
        while(k != 2*i-1){
            printf("*");
            ++k;
        }
        k=0;
        printf("\n");
    }
    return 0;
}

Output:

Enter the no. of rows:5
    *
   ***
  *****
 *******
*********

Program

#include<stdio.h>
int main()
{
    int a[3][2]={
        {5,0},
        {1,2},
        {2,3}},b[3][2]={
        {1,2},
        {2,3},
        {3,6}};
    int c[3][2];
    int i,j;

    for(i=0;i<3;i++)
        for(j=0;j<2;j++){
            c[i][j]=a[i][j]+b[i][j];
            printf("%d\t",c[i][j]);

            if(j==1)
                printf("\n");
        }
    return 0;
}

Output

6   2
3   5
5   9

Program

#include<stdio.h>
int main()
{
    int a[5][2]={
        {0,0},
        {1,2},
        {2,4},
        {3,6},
        {4,8}};
    int i,j;
    for(i=0;i<5;i++)
        for(j=0;j<2;j++){
            printf("%d\t",a[i][j]);
            if(j==1)
                printf("\n");
        }
    return 0;
}

Output

0   0
1   2
2   4
3   6
4   8

Program

#include<stdio.h>
int main()
{
    int a[5],i,sum=0;
    for(i=0;i<5;i++)
    {
        printf("Enter number %d:",i+1);
        scanf("%d",&a[i]);
        sum=sum+a[i];
    }
    printf("Sum=%d",sum);
    return 0;
}

Output

Enter number 1: 10
Enter number 2: 30
Enter number 3: 20
Enter number 4: 50
Enter number 5: 40
Sum = 150

Program

#include<stdio.h>
int main()
{
    int a[5]={10,20,30,40,50},i;
    for(i=0;i<5;i++)
        printf("a[%d]=%d\n",i,a[i]);
    return 0;
}

Output

a[0] = 10
a[1] = 20
a[2] = 30
a[3] = 40
a[4] = 50