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CS1322/p5/MergeSort.java

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+/**
+ *  <PRE>
+ *  MergeSort.java
+ *
+ *  Revisions: 1.0 Nov. 04, 2002
+ *               Created the MergeSort class
+ *			   1.1 Nov. 05, 2002
+ *				 Compiled, Finished, Commented
+ *
+ *  </PRE>
+ *
+ *	Collaboration Statement:
+ *    I worked on the homework assignment alone, using only             
+ *    course materials.
+ *  
+ *  Created with JCreatorLE, some indents are off when viewed through notepad
+ *    or EMACS
+ *
+ *  @author <A HREF="mailto:gtg184g@mail.gatech.edu">Jose Manuel Caban</A>
+ *  @version Version 1.1, Nov. 04, 2002
+ */
+
+public class MergeSort extends AbstractSort{
+	
+  ////////////////
+  //Constructors//
+  ////////////////
+  
+  /**
+   *Constructor for MergeSort
+   *@param arrayWrap, the array to be sorted
+   */
+  public MergeSort(ArrayWrapper arrayWrap){
+    super(arrayWrap);
+    
+  }
+ 	
+  ///////////
+  //Methods//
+  ///////////
+	
+  /**
+   *Sort the Array
+   */
+  public void doSort(){
+    Comparable[] tmpArray = new Comparable[arrayWrap.length()];
+    for(int i=0; i<arrayWrap.length(); i++){
+    	tmpArray[i] = arrayWrap.get(i);
+    }
+    mergeSort(tmpArray,0,tmpArray.length-1);    
+  }//end doSort()
+  
+  /**
+   *Recursive Function to sort 2 arrays
+   */
+  private void mergeSort(Comparable[] toSort, int iLeft, int iRight){
+  	if(iLeft < iRight){
+  		int center = (iLeft+iRight)/2;
+  		mergeSort(toSort,iLeft,center);
+  		mergeSort(toSort,center+1,iRight);
+  		merge(toSort,iLeft,center+1,iRight);
+  	}
+  }//end mergeSort()
+  
+  /**
+   *Merge arrays
+   */
+  private void merge(Comparable[] toSort, int iLeft, int iCenter, int iRight){
+  	int iLeftCounter 	= iLeft;
+  	int iRightCounter 	= iCenter;
+  	int iTempCounter  	= iLeft;
+  	int iLength			= (iRight - iLeft) + 1;
+  	
+  	
+  	while(iLeftCounter<=(iCenter-1) && iRightCounter<= iRight){
+  		if(arrayWrap.get(iLeftCounter).compareTo(
+  					arrayWrap.get(iRightCounter))<0){
+  			toSort[iTempCounter++] = arrayWrap.get(iLeftCounter++);
+  		}
+  		else{//you're off your rocker if you think im gonna write the if()
+  			toSort[iTempCounter++] = arrayWrap.get(iRightCounter++);
+  		}
+  	}
+  	
+  	while(iLeftCounter <= (iCenter-1)){
+  		toSort[iTempCounter++] = arrayWrap.get(iLeftCounter++);
+  	}
+  	
+  	while(iRightCounter <= iRight){
+  		toSort[iTempCounter++] = arrayWrap.get(iRightCounter++);
+  	}
+  	
+  	for(int i=0; i<iLength; i++,iRight--){
+  		arrayWrap.set(iRight,toSort[iRight]);
+  	}
+  }//end merge()
+
+
+  /**
+   *  Debugging main for class MergeSort.  
+   *  This method will rigorously test my code.
+   *
+   *  <br><br>
+   *  @param args a String array of command line arguments.
+   */
+  public static void main(String[] args) {
+    ArrayWrapper aw = new ArrayWrapper(ArrayWrapper.getRandomIntegerArray(40));    
+    MergeSort M$ = new MergeSort(aw); //ok, actually i HATE ppl who say M$
+    							//except T.A.'s who say it..
+    
+    for(int i=0;i<aw.length();i++){
+    	System.out.println(aw.get(i));
+    }
+    M$.doSort();
+    System.out.println("\n/****Testing Now****/\n");
+    for(int i=0;i<aw.length();i++){
+    	System.out.println(aw.get(i));
+	}
+    
+  }// end of main(String[] args)
+
+}// end of class MergeSort