public void nextPermutation(int[] nums) {

int n = nums.length;

if(n > 0){

// Find suffix length

int r = n-1;

while(r > 0){

if(nums[r-1] >= nums[r]){

r--;

} else {

break;

}

}

if(r > 0){

int pivot = r-1;

int q = r;

for(int i=r; i < n; i++){

if(nums[i] <= nums[q] && nums[i] > nums[pivot]) q = i;

}

swap(nums, pivot, q);

}

reverse(nums, r, n-1);

}

}

public void reverse(int[] nums, int start, int end){

while(start < end){

swap(nums, start, end);

start++;

end--;

}

}

public void swap(int[] nums, int i, int j){

int tmp = nums[i];

nums[i] = nums[j];

nums[j] = tmp;

}

}