selection sort in c

#include<stdio.h>

main()
{
   int array[100], n, c, d, position, swap;

   printf("Enter number of elements\n");
   scanf("%d", &n);

   printf("Enter %d integers\n", n);

   for ( c = 0 ; c < n ; c++ )
      scanf("%d", &array[c]);

   for ( c = 0 ; c < ( n - 1 ) ; c++ )
   {
      position = c;

      for ( d = c + 1 ; d < n ; d++ )
      {
         if ( array[position] > array[d] )
            position = d;
      }
      if ( position != c )
      {
         swap = array[c];
         array[c] = array[position];
         array[position] = swap;
      }
   }

   printf("Sorted list in ascending order:\n");

   for ( c = 0 ; c < n ; c++ )
      printf("%d\n", array[c]);

   return 0;
}

Swapping numbers using call by reference

#include <stdio.h>

void swap(int*, int*);

int main()
{
   int x, y;

   printf("Enter the value of x and y\n");
   scanf("%d%d",&x,&y);

   printf("Before Swapping\nx = %d\ny = %d\n", x, y);

   swap(&x, &y);

   printf("After Swapping\nx = %d\ny = %d\n", x, y);

   return 0;
}

void swap(int *a, int *b)
{
   int temp;

   temp = *b;
   *b = *a;
   *a = temp;  
}

c program to find frequency of characters in a string

#include<stdio.h>
#include<string.h>

main()
{
   char string[100], ch;
   int c = 0, count[26] = {0};

   printf("Enter a string\n");
   gets(string);

   while ( string[c] != '\0' )
   {
      /* Considering characters from 'a' to 'z' only */

      if ( string[c] >= 'a' && string[c] <= 'z' )
         count[string[c]-'a']++;

      c++;
   }

   for ( c = 0 ; c < 26 ; c++ )
   {
      if( count[c] != 0 )
         printf("%c occurs %d times in the entered string.\n",c+'a',count[c]);
   }

   return 0;
}

c program to reverse a number

//C Program to reverse a number :- This program reverse the number entered by the user and then prints the reversed number on the screen.

#include <stdio.h>
 main()

{
int n, reverse = 0;
printf("Enter a number to reverse\n");
scanf("%d",&n);
while (n != 0)
{
reverse = reverse * 10;

reverse = reverse + n%10; n = n/10;

}

printf("Reverse of entered number is = %d\n", reverse);

return 0;

}

SORTING MATRIX

//Sorting Matrix

#include <stdio.h>
void main ()
{
 int ma[10][10],mb[10][10];
int i,j,k,a,m,n;
printf ("Enter the order of the matrix \n");
scanf ("%d %d", &m,&n);
printf ("Enter co-efficients of the matrix \n");
for (i=0;i<m;++i)
{
for (j=0;j<n;++j)
{
scanf ("%d",&ma[i][j]);
mb[i][j] = ma[i][j];
}
}
printf ("The given matrix is \n");
for (i=0;i<m;++i)
{
for (j=0;j<n;++j)
{
printf (" %d",ma[i][j]);
}
printf ("\n");
}
printf ("After arranging rows in ascending order\n");
for (i=0;i<m;++i)
{
for (j=0;j<n;++j)
{
for (k=(j+1);k<n;++k)
{
if (ma[i][j] > ma[i][k])
{
a = ma[i][j];
ma[i][j] = ma[i][k];
ma[i][k] = a;
}
}
}
}
for (i=0;i<m;++i)
{
for (j=0;j<n;++j)
{
printf (" %d",ma[i][j]);
}
printf ("\n");
}
printf ("After arranging the columns in descending order \n");
for (j=0;j<n;++j)
{
for (i=0;i<m;++i)
{
for (k=i+1;k<m;++k)
{
if (mb[i][j] < mb[k][j])
{
a = mb[i][j];
mb[i][j] = mb[k][j];
mb[k][j] = a;
}
}
}
}
for (i=0;i<m;++i)
{
for (j=0;j<n;++j)
{
printf (" %d",mb[i][j]);
}
printf ("\n");
}
}

C programm print Pyramid of Stars

#include<stdio.h>

main()
{
   int row, c, n, temp;

   printf("Enter the number of rows in pyramid of stars you wish to see ");
   scanf("%d",&n);

   temp = n;


   for ( row = 1 ; row <= n ; row++ )
   {
      for ( c = 1 ; c < temp ; c++ )
         printf(" ");

      temp--;

      for ( c = 1 ; c <= 2*row - 1 ; c++ )
         printf("*");

      printf("\n");
   }

   return 0;
}

C program to compare two strings without using library function

// c program to compare two strings without using library functions

#include <stdio.h>

int main()

{

char a[50];

char b[50];

int i, j, nr1=0, nr2=0;

printf("enter the two strings you want to compare\n");

scanf("%s %s", a, b);

//counting the length of each string

while(a[i]!=\0)

{

nr1++;

i++;

}

while(b[j]!=\0)

{

nr2++;

j++;

}

if(nr1 != nr2)

{

printf("NO different lengths");

return 0;

}

for(i=0;i<nr1;i++)

{if(a[i]!=b[j])

{ printf("NO");

return0;

}

}

printf("the strings are identic");

}