class Solution {
    public void nextPermutation(int[] nums) {
        int i=nums.length-2, j=nums.length-1, temp;
        while(i>-1 && nums[i]>=nums[i+1])
            i--;
        if(i>=0){
            while(nums[i]>=nums[j])
            j--;
        
            temp=nums[i];
            nums[i]=nums[j];
            nums[j]=temp;
        }
        int k=nums.length-1;
        i++;
        while(i<k){
            temp=nums[i];
            nums[i]=nums[k];
            nums[k]=temp;
            i++; k--;
        }
    }
}