// ----------------------------------------------------------------------------- 
//  DataPack class:  an array plus its management information.
//  Implementation file for all DataPack programs.                  datapack.cpp
//  Created by Alice Fischer on Mon August 23, 2009
// ----------------------------------------------------------------------------- 
#include "datapack.hpp"

// --------------------------------------------------------------------- 
//  Read (from user) name of input file and open it.  
//  Read up to max items from input stream and store in array. 
void 
DataPack::readData() {   
    char filename[80];      // For name of input file 
    cout << "Enter name of data file to be searched: ";
    cin.getline( filename, 80 );
    ifstream infile( filename ); 
    if (! infile)  fatal( "    Error: couldn't open input %s\n", filename ); 

    BT* cursor = store;     // Scanning pointer, set to start of array.     
    BT* end = store + max;  // An off-board sentinel 
 
    for( ; cursor<end; ++ cursor ) {
        infile >> *cursor;
        if( ! infile.good() ) break;    // Quit for bad data or for end of file.
    }
    n = cursor-store;                   // Actual # of items read. 
}

// --------------------------------------------------------------------- 
//  Print the data from the array. 
void 
DataPack :: printData( ostream& out ) {     
    for( int k=0; k<n; ++k) {  out << store[k] <<"\n"; }     
}

// --------------------------------------------------------------------- 
//  Sort data in the data pack.  The < and <= operators must be defined for BT.  
//
void 
DataPack :: sortData() {
    BT* const end = store + n;  // Off-board sentinel.  
    BT* pass;                   // First unsorted item; begin pass here.  
    BT  newcomer;               // Data value being inserted.  
    BT* hole;                   // Array slot containing no data.  
        
    for ( pass = &store[1]; pass<end; ++pass ) { 
        // Pick up next item and insert into sorted portion of array.  
        newcomer = *pass;
        for ( hole=pass; hole > store; --hole ) {
            if ( *(hole-1) <= newcomer ) break;   // Insertion slot is found. 
            *hole = *(hole-1);                    // Move item 1 slot rightward.  
        }
        *hole = newcomer;
    }
}