31. Next Permutation

31. Next Permutation/Solution.cs

@@ -0,0 +1,17 @@
+public class Solution
+{
+    public void NextPermutation(int[] nums)
+    {
+        var i = nums.Length - 2;
+        while(i >= 0 && nums[i] >= nums[i+1])
+            i--;
+        if(i >= 0)
+        {
+            var j = nums.Length - 1;
+            while(nums[i] >= nums[j])
+                j--;
+            (nums[i], nums[j]) = (nums[j], nums[i]);
+        }
+        Array.Reverse(nums, i+1, nums.Length-i-1);
+    }
+}