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MergeSortDemo.java
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MergeSortDemo.java
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import java.util.Arrays;
public class MergeSortDemo {
public static void main(String[] args) {
int[] nums={17,13,2,6,8,1,-19,45,67,42,3,2,0};
System.out.println("Input Array before sorting : "+ Arrays.toString(nums));
int sorted[]=doMergeSort(nums,0,nums.length-1);
System.out.println("Input Array After sorting using MergeSort Algorithm :"+Arrays.toString(sorted));
}
private static int[] doMergeSort(int[] nums, int low,int high) {
if (low<high) {
int mid=low+(high-low)/2;
doMergeSort(nums, 0, mid);
doMergeSort(nums,mid+1,high);
merge(low,mid,high,nums);
}
return nums;
}
private static void merge(int low, int mid, int high,int[] nums) {
int[] left=new int[mid-low+1];
int[] right=new int[high-mid];
for (int i = 0; i < left.length; i++) {
left[i]=nums[i+low];
}
for (int j = 0; j <right.length ; j++) {
right[j]=nums[mid+1+j];
}
int k=low;
int i=0,j=0;
while (i<left.length && j<right.length){
if(left[i]<right[j])
nums[k++]=left[i++];
else
nums[k++]=right[j++];
}
//copy the remaining elements
while (i<left.length)
nums[k++]=left[i++];
while (j<right.length)
nums[k++]=right[j++];
}
}