[Algorithm] Merge Sort (Recursion)

1. Merge Sort (Recursion)

void merge(int bb, int mm, int ee){
   int b = bb, k = bb, m = mm+1;
   while( b <= mm && m <= ee ) {
      if( A[ b ] <= A[ m ] ) S[ k++ ] = A[ b++ ];
      else                   S[ k++ ] = A[ m++ ];
   }
   if( b <= mm ) while( b <= mm ) S[ k++ ] = A[ b++ ];
   else          while( m <= ee ) S[ k++ ] = A[ m++ ];
   for( int i = bb; i <= ee; i++)
      A[ i ] = S[ i ];
}

void merge_sort(int bb, int ee){
   if( bb < ee ) {
      int mm = (bb + ee) / 2;
      merge_sort( bb, mm ); 
      merge_sort( mm+1, ee ); 
      merge( bb, mm, ee );
   }
}