Binary Search Program Using C Programming Language

 #include   <stdio.h>

int  RecursiveBinarySearch( int  data[],  int  low,  int  high,  int  key);

int  main() {

int  key, index;

printf( "Binary Search : \n" );

printf( "\n" );

int  data[] = { 1, 2, 4, 5, 7, 9, 12, 15, 16, 17, 20, 24, 27, 28, 36, 38, 44, 45, 48, 50, 51, 52, 54, 56, 60, 64, 72, 75, 77, 79, 80, 81, 89, 94, 98, 100, 104, 116, 124, 156, 157, 164, 182, 200 };

printf( "Element to be searched = " );

scanf( "%d" ,&key);

printf( "\n" );

index = RecursiveBinarySearch(data, 0,  sizeof (data) /  sizeof (*data), key);

if  (index == -1) {

printf( "Key not found! \n" );

}

else  {

printf( "Key found at index : %d \n" , index);

}

printf( "\n" );

return  0;

}

int  RecursiveBinarySearch( int   data [],  int   low ,  int   high ,  int   key ) {

int  mid;

if  ( low  <=  high ) {

mid = ( low  +  high ) / 2;

if  ( data [mid] ==  key ) {

return  mid;

}

else   if  ( data [mid] >  key ) {

return  RecursiveBinarySearch( data ,  low , (mid - 1),  key );

}

else  {

return  RecursiveBinarySearch( data , (mid + 1),  high ,  key );

}

}

return  -1;

}