31. Next Permutation

]>class Solution {
public:
    void nextPermutation(vector<int>& nums) {
        int length = nums.size();
        if(length <= 0)
            return;
        int j;
        for(int i = length - 2;i >= 0;i--){
            if(nums[i+1] > nums[i]){
                for(j = length - 1;j > i;j--){
                    if(nums[j] > nums[i])
                        break;
                }
                swap(nums[j],nums[i]);
                reverse(nums.begin() + i + 1,nums.end());
                return;
            }
        }
        reverse(nums.begin(),nums.end());
    }
};