TypeIIRMLQuicksort.cpp

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#include <TypeIIRMLQuicksort.h>


//************************************************************************************
// Quicksort()


void TypeIIRMLMath::Quicksort(      const int   &LeftBound
                                ,   const int   &RightBound
                                ,   double      *ArrayOfValues)
{
    int             FirstLoopVariable
                ,   SecondLoopVariable;

    double          CurrentValue
                ,   HelpVariable;

    CurrentValue        =   ArrayOfValues[(LeftBound + RightBound) / 2] ;
    FirstLoopVariable   =   LeftBound                                   ;
    SecondLoopVariable  =   RightBound                                  ;

    // try to interexchange elements from the left and from the right
    while ( FirstLoopVariable <= SecondLoopVariable )
    {
        while( ArrayOfValues[FirstLoopVariable] < CurrentValue )
        {
            FirstLoopVariable = FirstLoopVariable + 1;
        }

        while ( ArrayOfValues[SecondLoopVariable] > CurrentValue )
        {
            SecondLoopVariable = SecondLoopVariable - 1;
        }

        if ( FirstLoopVariable <= SecondLoopVariable )
        {
            // Interexchange ArrayOfValues[i] and ArrayOfValues[j]
            HelpVariable                        =   ArrayOfValues[FirstLoopVariable]    ;
            ArrayOfValues[FirstLoopVariable]    =   ArrayOfValues[SecondLoopVariable]   ;
            ArrayOfValues[SecondLoopVariable]   =   HelpVariable                        ;
            FirstLoopVariable                   =   FirstLoopVariable + 1               ;
            SecondLoopVariable                  =   SecondLoopVariable - 1              ;
        }
    }

    // Recursive call for both subsections
    if ( LeftBound < SecondLoopVariable )
    {
        Quicksort(      LeftBound
                    ,   SecondLoopVariable
                    ,   ArrayOfValues       );
    }

    if ( FirstLoopVariable < RightBound )
    {
        Quicksort(      FirstLoopVariable
                    ,   RightBound
                    ,   ArrayOfValues       );
    }
}