Minimum_Adjacent_Swaps_to_Reach_Kth_Smallest_Number

class Solution {
    public int getMinSwaps(String num, int k) {
        char[] target = num.toCharArray();
        for(int i=0;i<k;i++)
        {
            nextPermutation(target);
        }
        char[] nums = num.toCharArray();
        return minswaps(nums,target,nums.length);
    }
    
    public void reverse(char[] nums,int i)
    {
        int j=nums.length-1;
        while(i<j){
            swap(nums,i,j);
            i++;
            j--;
        }
    }
    
    public void swap(char[] nums, int i,int j)
    {
        char temp = nums[i];
        nums[i] = nums[j];
        nums[j] = temp;
    }
    
    public void nextPermutation(char[] nums)
    {
        if(nums.length==0) return;
        int len=nums.length;
        for(int i=len-1;i>=1;i--)
        {
            if(nums[i]>nums[i-1])
            {
                reverse(nums,i);
                for(int j=i;j<len;j++)
                {
                    if(nums[j]>nums[i-1]){
                        swap(nums,i-1,j);
                        return;
                    }
                }
            }
        }
        reverse(nums,0);
    }
    
    public int minswaps(char[] nums, char[] target, int size){
        int j=0,swaps=0;
        for(int i=0;i<size;i++)
        {
            j=i;
            while(nums[j]!=target[i]) j++;
            while(i<j)
            {
                swap(nums,j,j-1);
                j--;
                swaps++;
            }
            
        }
        return swaps;
    }
    
    
    
    
    
    
    
    
}