binary-search.c

#include <stdio.h>

int bsearch( char to_search, char array[], int min, int max )
{
   int middle = min + ( ( max - min ) / 2 );
   if ( ( min == max ) && ( array[ min ] != to_search ) )
      return -1;
   if ( array[ min ] == to_search )
      return min;
   if ( array[ max ] == to_search )
      return max;
   if ( array[ middle ] == to_search )
      return middle;
   if ( to_search >= array[ middle ] ) {
      return bsearch( to_search, array, middle, max );
   }
   else {
      return bsearch( to_search, array, min, middle );
   }
}

int main( int argc, char* argv[] )
{
   char array[ 10 ] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j' };

   fprintf( stdout, "%i\n", bsearch( argv[ 1 ][ 0 ], array, 0, sizeof( array ) ) );

   return 0;
}