MergeSort

/*
 * Created on Sep 21, 2004
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package com.custommode;
/**
 * @author damelchenko
 *  
 */
public class MergeSort {
    public static void main(String args[]) {
        int[] mParams = new int[args.length];
        for (int i = 0; i < mParams.length; i++) {
            mParams[i] = new Integer(args[i]).intValue();
        };
        int[] mResults = sort(mParams);
        for (int i = 0; i < mResults.length; i++) {
            System.out.print(mResults[i]);
            System.out.print(" ");
        }
    }
    /**
     * recursive sort method
     * 
     * @param pUnsordetArray
     * @return returns sorted array
     */
    public static int[] sort(int[] pUnsordetArray) {
        if (pUnsordetArray.length <= 1)
            return pUnsordetArray;//it's sorted
        int[] mLeftArray = new int[pUnsordetArray.length / 2
                + pUnsordetArray.length % 2];
        int[] mRighArray = new int[pUnsordetArray.length / 2];
        for (int i = 0; i < pUnsordetArray.length / 2 + pUnsordetArray.length
                % 2; i++) {
            mLeftArray[i] = pUnsordetArray[i];
        }
        for (int i = 0; i < pUnsordetArray.length / 2; i++) {
            mRighArray[i] = pUnsordetArray[i + pUnsordetArray.length / 2
                    + pUnsordetArray.length % 2];
        }
        mLeftArray = sort(mLeftArray);
        mRighArray = sort(mRighArray);
        int[] mResultMerge = merge(mLeftArray, mRighArray);
        return mResultMerge;
    }
    public static int[] merge(int[] pLeftArray, int[] pRightArray) {
        int[] mResultMerge = new int[pLeftArray.length + pRightArray.length];
        int mResultIndex = 0, mLowPointer = 0, mHighPointer = 0;
        for (mResultIndex = 0; mResultIndex < mResultMerge.length; mResultIndex++) {
            if(mLowPointer >= pLeftArray.length) {
                for(int j = mHighPointer; j < pRightArray.length; ) {
                    mResultMerge[mResultIndex++] = pRightArray[j++];
                }
                return mResultMerge;
            }
            if(mHighPointer >= pRightArray.length) {
                for(int j = mLowPointer; j < pLeftArray.length; ) {
                    mResultMerge[mResultIndex++] = pLeftArray[j++];
                }
                return mResultMerge;
            }
            
            if(pLeftArray[mLowPointer] < pRightArray[mHighPointer]) {
                mResultMerge[mResultIndex] = pLeftArray[mLowPointer++];
            } else {
                mResultMerge[mResultIndex] = pRightArray[mHighPointer++];
            }
        }
        return mResultMerge;
    }
}