C language code to display the pattern:

#include<stdio.h>
#include<conio.h>
void main()
{
int noofrows,rows,col1,col2,noofcols;
clrscr();
printf ("Enter the number: ");
scanf ("%d",&noofrows);
noofcols=noofrows-1;
for(rows=1;rows<=noofrows;rows++)
       {
for(col1=1;col1<=noofcols;col1++)
       {
printf(" ");
       }
noofcols--;
for(col2=1;col2<=rows;col2++)
       {
printf (" *");
       }
printf ("\n");
       }
getch ();
}

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Output:

Enter the number:5
                      *
                    *  *
                  *  *  *
                *  *  * *
             *  *  *  *  *

                 

                              Fibonacci series means if we are giving input as 7 then the output is 0  1  1  2  3  5.
Means in output first digit is 0 then second is 1,addition of first and second digit is third digit i.e.0+1=1,next is 1+1=2,then 2+1=3,then 3+2=5.
                    The next digit is 5+3=8 but 8 is greater than 7(8>7) i.e.(8!<7) so the control is transfer to the
out of the loop.The actual code is as follows:

code:

#include<stdio.h>
#include<conio.h>
void main()
{
int no,a=0,b=1,c=0;
clrscr();
printf("Enter the number to print fibonacci series:");
scanf("%d",&no);
while(no>c)
{
printf("%d  ",c);
c=a+b;
b=a;
a=c;
}
getch();
return 0;
}
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Output:
           Enter the number to print fibonacci series:7
           0  1  1  2  3  5
     

SWAPPING OF TWO NUMBERS:
#include<studio.h>
#include<condo.h>
int main()
{
int a, b;
clrscr();
printf("ENTER TWO NUMBERS: \n");
scanf("%d%d",&a,&b);
a=a+b;
b=a-b;
a=a-b;
printf("a=%d\n b=%d\n", a, b);
getch();
}
__________________________________________________________
Output:
ENTER TWO NUMBERS:13
                                            45
a=45
b=13