Leetcode Next Permutation problem solution

class Solution(object):
    def nextPermutation(self, nums):
        """
        :type nums: List[int]
        :rtype: void Do not return anything, modify nums in-place instead.
        """
        
        lenn = len(nums)
        
        if lenn < 2:
            return
        
        a = [nums[-1]]
        
        for i in range(lenn-2,-1,-1):
            if nums[i] < nums[i+1]:
                m = i+1
                for j in range(i+1,lenn):
                    if nums[j] > nums[i]:
                        if nums[j] < nums[i+1]:
                            m = j
                
                nums[i], nums[m] = nums[m], nums[i]
                
                nums[i+1:] = sorted(nums[i+1:])
                
                return
        
        for i in range(lenn//2):
            nums[i],nums[lenn-1-i] = nums[lenn-1-i],nums[i]

public static void nextPermutation(int[] nums) {
            if (nums == null || nums.length == 0) return;

            int maxElementIndex = nums.length-1;
            for (int i=nums.length-2;i>=0;i--) {
                if (nums[maxElementIndex]< nums[i]) maxElementIndex = i;
                if(nums[i] < nums[i+1]) {
                    for (int j=nums.length-1;j>i;j--) {
                        if (nums[j] > nums[i]){
                            maxElementIndex = j;
                            break;
                        }
                    }
                    swap(nums, i, maxElementIndex);
                    Arrays.sort(nums, i+1, nums.length);
                    return;
                }
            }

            Arrays.sort(nums);
        }

        private static void swap(int[] nums, int i, int j) {
            int temp = nums[i];
            nums[i] = nums[j];
            nums[j] = temp;
        }

class Solution {
public:
    void nextPermutation(vector<int>& nums) {
        int i = nums.size()-1;
        if(nums.size()==1) return;
        while(i>0 && nums[i] <= nums[i-1]) i--;
        if(i != 0){
            for(int j=nums.size()-1;j>=i;j--){
                if(nums[j]>nums[i-1]){
                    swap(nums[j],nums[i-1]);
                    break;
                } 
            }    
        }
        int j = nums.size()-1;
        while(i<j) swap(nums[i],nums[j]),i++,j--;
        
    }
};

void nextPermutation(int* nums, int numsSize)
{
    int i, j;
    int t = -1;
    for (i = numsSize - 1; i > 0; --i) {
        if (nums[i - 1] < nums[i]) {
            t = i - 1;
            break;
        }
    }
    for (i = t + 1, j = numsSize - 1; i < j; ++i, --j) {
        nums[i] ^= nums[j];
        nums[j] ^= nums[i];
        nums[i] ^= nums[j];
    }
    if (t >= 0) {
        for (i = t + 1; i < numsSize; ++i) {
            if (nums[i] > nums[t]) {
                nums[i] ^= nums[t];
                nums[t] ^= nums[i];
                nums[i] ^= nums[t];
                break;
            }
        }
    }
}