[Algorithm] Merge Sort (Iteration)

1. Merge Sort (Iteration)

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) {
   #define min(a,b) ((a) < (b) ? (a) : (b))
   for( int k = 1; k <= ee; k *= 2 ) {
      for ( int i = bb; i <= ee; i += k*2 ) {
         merge(i, min(i+k-1, ee), min(i+k*2-1, ee));
      }
   }
}