SOlution for: Permutations array

Author: edyluisrey

src/leetcode/Permutations.java

@@ -0,0 +1,42 @@
+package leetcode;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Permutations {
+
+	public static void main(String[] args) {
+		Permutations test = new Permutations();
+		System.out.println(test.permute(new int[]{1,2,3}));
+	}
+	
+	public List<List<Integer>> permute(int[] nums) {
+		List<List<Integer>> list = new ArrayList<>();
+		helper(nums,0,nums.length-1,list);
+	    return list;
+	}
+	
+	public void helper(int[] nums, int l, int tam, List<List<Integer>> list){       
+	    if(l==tam){
+	        List<Integer> newList= new ArrayList<>();
+	        for(int i=0;i<=tam;i++){
+	            newList.add(nums[i]);
+	        }
+	        list.add(newList); 
+	    }else{
+	        for(int j=l; j<=tam;j++){
+	            nums= swap(nums,l,j);
+	            helper(nums,l+1,tam,list);
+	            nums = swap(nums,l,j);
+	        }
+	    }
+	}
+	
+	public int[] swap(int[] nums,int i, int j){
+	    int tem = nums[i];
+	    nums[i]=nums[j];
+	    nums[j]= tem;
+	    return nums;
+	}
+
+}