Data commit

Task/Sorting-algorithms-Permutation-sort/Java/sorting-algorithms-permutation-sort.java

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+import java.util.List;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+public class PermutationSort
+{
+	public static void main(String[] args)
+	{
+		int[] a={3,2,1,8,9,4,6};
+		System.out.println("Unsorted: " + Arrays.toString(a));
+		a=pSort(a);
+		System.out.println("Sorted: " + Arrays.toString(a));
+	}
+	public static int[] pSort(int[] a)
+	{
+		List<int[]> list=new ArrayList<int[]>();
+		permute(a,a.length,list);
+		for(int[] x : list)
+			if(isSorted(x))
+				return x;
+		return a;
+	}
+	private static void permute(int[] a, int n, List<int[]> list)
+	{
+		if (n == 1)
+		{
+			int[] b=new int[a.length];
+			System.arraycopy(a, 0, b, 0, a.length);
+			list.add(b);
+		    return;
+		}
+		for (int i = 0; i < n; i++)
+		{
+		        swap(a, i, n-1);
+		        permute(a, n-1, list);
+		        swap(a, i, n-1);
+		 }
+	}
+	private static boolean isSorted(int[] a)
+	{
+		for(int i=1;i<a.length;i++)
+			if(a[i-1]>a[i])
+				return false;
+		return true;
+	}
+	private static void swap(int[] arr,int i, int j)
+	{
+		int temp=arr[i];
+		arr[i]=arr[j];
+		arr[j]=temp;
+	}
+}