下一个排列

[1,3,2,3]

[1,3,3,2]

[4,3,2,1]

[1,2,3,4]

class Solution {
public:
/**
* @param nums: An array of integers
* @return: An array of integers that's next permuation
*/
vector<int> nextPermutation(vector<int> &nums) {
// write your code here
int n = nums.size();
int i = n-1;
for (; i > 0; i--)
{
if (nums[i] > nums[i-1])
{
int j = n-1;
for (; j >= i; j--)
{
if (nums[j] > nums[i-1])
{
break;
}
}
swap(nums[i-1], nums[j]);
int left = i;
int right = n-1;
while (left < right)
{
swap(nums[left], nums[right]);
left++;
right--;
}

break;
}
}

if (i == 0)
{
int left = 0;
int right = n-1;
while (left < right)
{
swap(nums[left], nums[right]);
left++;
right--;
}
}

return nums;
}
};