### Find Largest & Second Largest Number -C Program

Program:
#include<stdio.h>
//#include<conio.h>
//void
main()
{
int i,l,a[100],sl,n;
printf("Enter the limit: ");
scanf("%d",&n);
printf("Enter the elements:\n");
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
}
l=a[0];
sl=a[1];
for(i=0;i<n;i++)
{
if(a[i]>l)
{
sl=l;
l=a[i];
}
}
for(i=0;i<n;i++)
{
if(a[i]>sl && a[i]!=l)
{
sl=a[i];
}
}
printf("largest=%d\n",l);
printf("second largest=%d\n",sl);
//    getch();
}

Output:
nn@linuxmint ~ \$ gcc c5.c
nn@linuxmint ~ \$ ./a.out
Enter the limit: 5
Enter the elements:
5
4
3
2
1
largest=5
second largest=4
nn@linuxmint ~ \$

### Generation of Fibonacci Series -C Program

Program:
#include<stdio.h>
//#include<conio.h>
void main()
{
int a[200];int i,n,t1=1,t2=1,t3,x,y;//clrscr();
a[1]=1;a[2]=1;
printf("Enter the no of terms:");
scanf("%d",&n);
if(n<=0)
printf("Error..!");
else if(n==1)
printf("The fibonacci series:\n1");
else if(n==2)
printf("The fibonacci series:\n1,1");
else
printf("The fibonacci series:\n1,1");
for(i=3;i<=n;i++)
{
t3=t1+t2;
t1=t2;
t2=t3;
printf(",%d",t2);
a[i]=t3;
}
printf(",...\n");
//getch();
}

Output:
nn@linuxmint ~ \$ gcc c4.c
nn@linuxmint ~ \$ ./a.out
Enter the no of terms:5
The fibonacci series:
1,1,2,3,5,...
nn@linuxmint ~ \$

### Towers of Hanoi - C Program

Program:
#include<stdio.h>
//#include<conio.h>
void hanoi(int,int,int,int);
void main()
{
int no_of_disks, firstpeg=1,secondpeg=2,thirdpeg=3;//clrscr();;
printf("Enter the no. of disks:");
scanf("%d",&no_of_disks);
printf("\n\n Tower of Hanoi problem with %d disks. \n\n", no_of_disks);
hanoi(no_of_disks,firstpeg,secondpeg,thirdpeg);
printf("\nSolved...\n");//getch();
}

void hanoi(int n,int peg1,int peg2,int peg3)
{
if(n!=0)
{
hanoi(n-1,peg1,peg3,peg2);
printf("move disk %d from peg%d to peg%d \n",n,peg1,peg3);
hanoi(n-1,peg2,peg1,peg3);
}
}

Output:
nn@linuxmint ~ \$ gcc c21.c
nn@linuxmint ~ \$ ./a.out
Enter the no. of disks:3

Tower of Hanoi problem with 3 disks.

move disk 1 from peg1 to peg3
move disk 2 from peg1 to peg2
move disk 1 from peg3 to peg2
move disk 3 from peg1 to peg3
move disk 1 from peg2 to peg1
move disk 2 from peg2 to peg3
move disk 1 from peg1 to peg3

Solved...
nn@linuxmint ~ \$

### Generation of Prime Numbers - C Program

Program:
#include<stdio.h>
//#include<math.h>
//#include<conio.h>
main()
{
int i,a,b,j,flag=1;//clrscr();
printf("\nEnter the limit:\n");
scanf("%d%d",&a,&b);
for(i=a;i<=b;i++)
{
if (i==0||i==1)
continue;
flag=1;
for(j=2;j<=(i/2);j++) //sqrt(i) can be used.
{
if(i%j==0)
{
flag=0;
}
}
if(flag==1)
{
printf("%d\t",i);
}
}
// getch();
printf("\n");
}

Output:
nn@linuxmint ~ \$ gcc c3.c
nn@linuxmint ~ \$ ./a.out

Enter the limit:
1
10
2    3    5    7
nn@linuxmint ~ \$