79 lines
1.6 KiB
Java
79 lines
1.6 KiB
Java
//Java program for implementation of Merge Sort
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import java.util.*;
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class MergeSortApp
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{
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private int[] arr;
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public MergeSortApp()
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{
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arr = new int[]{12,54,222,54622,10,169,30}; //Array to sort
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}
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//Funtion to display/Print Array
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public void printArray()
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{
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for (int i=0;i<arr.length;i++)
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{
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System.out.print(arr[i]+ " ");
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}
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System.out.println();
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}
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//Function called by main()
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public void mergesort()
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{
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int[] wr = new int[arr.length]; //Provides workspace
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recMergeSort(wr,0,wr.length-1);
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}
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//Recursive function to divide array in halves
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public void recMergeSort(int[] wr,int lowBound,int uppBound)
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{
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if (lowBound == uppBound)
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return;
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else
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{
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int mid = (lowBound+uppBound)/2; //find midpoint
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recMergeSort(wr,lowBound,mid); //Sort low half
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recMergeSort(wr,mid+1,uppBound); // Sort high half
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merge(wr,lowBound,mid+1,uppBound); //merge them
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}
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}
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//Function to merge sorted Arrays
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public void merge(int[] wr,int lowptr,int highptr, int uppBound)
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{
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int j=0;
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int lowBound = lowptr;
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int mid = highptr-1;
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int n = uppBound-lowBound+1;
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while (lowptr<=mid && highptr<=uppBound)
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{ if (arr[lowptr]<arr[highptr])
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wr[j++] = arr[lowptr++];
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else
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wr[j++] = arr[highptr++];
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}
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while (lowptr<=mid)
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wr[j++] = arr[lowptr++];
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while(highptr<=uppBound)
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wr[j++] = arr[highptr++];
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for (j=0;j<n;j++)
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arr[lowBound+j] = wr[j];
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}
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}
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class MergeSort
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{ //Driver code to test above code
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public static void main(String[] args)
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{
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MergeSortApp ob = new MergeSortApp(); //creates object
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ob.printArray(); //Displays Array before sorting
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ob.mergesort();
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ob.printArray();
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}
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} |