31. Next Permutation

Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.
If such arrangement is not possible, it must rearrange it as the lowest possible order (ie, sorted in ascending order).
The replacement must be in-place, do not allocate extra memory.
Here are some examples. Inputs are in the left-hand column and its corresponding outputs are in the right-hand column.
1,2,3 → 1,3,2
3,2,1 → 1,2,3
1,1,5 → 1,5,1

public class Solution {
    public void nextPermutation(int[] nums) {
        int i = nums.length-1,pivot = -1;
        for(;i>0;i--)       //先找到从左到右递减的位置
           if(nums[i]>nums[i-1])
              {
                  pivot = i-1;
                  break;
              }
        if(pivot>=0)
          {
              for(int j=nums.length-1;j>pivot;j--)
                {
                    if(nums[j]>nums[pivot])//然后找出比nums[pivot]大且最接近的数
                       {
                           int temp = nums[j];
                           nums[j] = nums[pivot];
                           nums[pivot] = temp;
                           Arrays.sort(nums,pivot+1,nums.length);
                           return;
                       }
                }
          }
        else
          Arrays.sort(nums);
        return;
              
    }
}