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--;
        }
    }
}

class Solution {
    public static List<List<String>> displayTable(List<List<String>> orders) {
        int table; String food;
        Map<Integer, TreeMap<String, Integer>> map = new TreeMap<>();
        Set<String> set = new TreeSet<>();
        for (List<String> order : orders) {
            table = Integer.parseInt(order.get(1));food = order.get(2);
            set.add(food);
            TreeMap<String, Integer> foodMap;
            if (map.get(table) == null) foodMap = new TreeMap<>();
            else foodMap = map.get(table);
            foodMap.put(food, foodMap.getOrDefault(food, 0) +1);
            map.put(table, foodMap);
        }

public List<String> subdomainVisits(String[] cpdomains) {
        Map<String, Integer> map = new HashMap<>(); String website, websites[]; int number; StringBuilder sb;
        for(String s: cpdomains){
            sb=new StringBuilder(); number=Integer.parseInt(s.split(" ")[0]);
            websites=s.split(" ")[1].split("\\.");
            for(int i=websites.length-1; i>0; i--){
                sb.insert(0, websites[i]);
                map.put(sb.toString(), map.getOrDefault(sb.toString(), 0) +number);
                sb.insert(0, ".");
            } sb.insert(0, websites[0]);
            map.put(sb.toString(), map.getOrDefault(sb.toString(), 0) +number);
        } List<String> list = new ArrayList<>();
        for(Map.Entry<String, Integer> entry: map.entrySet()){
            sb=new StringBuilder();
            sb.append(entry.getValue()).append(" ").append(entry.getKey());
            list.add(sb.toString());
        } return list;}

class Solution {
    public void rotate(int[][] matrix) {
        int n=matrix.length, temp;
        for(int i=0; i<n/2; i++){
            for(int j=0; j<(n+1)/2; j++){
                temp=matrix[i][j];
                matrix[i][j]=matrix[n-1-j][i];
                matrix[n-1-j][i]=matrix[n-1-i][n-1-j];
                matrix[n-1-i][n-1-j]=matrix[j][n-1-i];
                matrix[j][n-1-i]=temp;
            }
        }
    }
}

class Solution {
    public int lengthOfLongestSubstring(String s) {
        if (s.length()==0) return 0;
        HashMap<Character, Integer> map = new HashMap<Character, Integer>();
        int max=0;
        for (int i=0, j=0; i<s.length(); ++i){
            if (map.containsKey(s.charAt(i))){
                j = Math.max(j,map.get(s.charAt(i))+1);
            }
            map.put(s.charAt(i),i);
            max = Math.max(max,i-j+1);
        }
        return max;
    }
}

class Solution {
    public int minPartitions(String n) {
        for(int i=9; i>=0; i--){
            if(n.contains(""+i))
                return i;
        }
        return -1;
    }
}

class Solution {
    public String convert(String s, int n) {
        if(n==1) return s;
        StringBuilder sb = new StringBuilder();
        for(int i=0; i<n; i++){
            for(int j=i; j<s.length(); ){
                sb.append(s.charAt(j));
                if(i!=0 && i!=n-1 && j<s.length()-(n-i-1)*2){
                    sb.append(s.charAt(j+(n-i-1)*2));
                }
                j=j+2*n-2;
            }
        }
        return sb.toString();
    }
}

class Solution {
    public int reverse(int x) {
        int res=0;
        boolean isPos=true;
        if(x<0){
            x=-x;
            isPos=false;
        }
        while(x>0){
            int last=x%10;
            x/=10;
            if(res>Integer.MAX_VALUE/10||res==Integer.MAX_VALUE/10 && last>=8) return 0;
            res=res*10+last;
            System.out.println(res);
        }
        return isPos ? res : -res;
    }
}

class Solution {
    public List<List<Integer>> threeSum(int[] nums) {
        Set<List<Integer>> set = new HashSet<>();
        Arrays.sort(nums);
        for(int i=0; i<nums.length-2; i++){
            int j=i+1, k=nums.length-1;
            while(j<k){
                int sum=nums[i]+nums[j]+nums[k];
                if(sum==0) set.add(Arrays.asList(nums[i], nums[j++], nums[k--]));
                else if(sum>0) k--;
                else j++;
            }
        }
        return new ArrayList<>(set);
    }
}

class Solution {
    public int threeSumClosest(int[] nums, int target) {
        int min=Integer.MAX_VALUE, res=-1000;
        Arrays.sort(nums);
        for(int i=0; i<nums.length-2; i++){
            int j=i+1, k=nums.length-1;
            while(j<k){
                int sum=nums[i]+nums[j]+nums[k];
                if(sum>=target) k--;
                else j++;
                if(Math.abs(sum-target)<min){
                    min=Math.abs(sum-target);
                    res=sum;
                }
            }
        }
        return res;
    }
}

class Solution {
    public ListNode removeNthFromEnd(ListNode head, int n) {
        ListNode start = new ListNode();
        ListNode slow=start, fast=start;
        start.next=head;
        while(n-- +1 >0){
            fast=fast.next;
        }
        
        while(fast!=null){
            fast=fast.next;
            slow=slow.next;
        }
        slow.next=slow.next.next;
        return start.next;
    }
}

class MyCalendar {
    Set<Pair<Integer, Integer>> set = new HashSet<>();
    public MyCalendar() {}
    public boolean book(int start, int end) {
        Pair<Integer, Integer> pair = new Pair<>(start, end);
        for(Pair<Integer, Integer> s: set){
            if(s.getKey() < end && start < s.getValue()){
                return false;
            }
        }
        set.add(pair);
        return true;
    }
}

class Solution {
    public int minSetSize(int[] arr) {
        int count=0, sum=0;
        Map<Integer, Integer> map = new HashMap<>();
        for(int n: arr){
            map.put(n, map.getOrDefault(n, 0) +1);
        }
        List<Map.Entry<Integer, Integer>> list = new LinkedList<>(map.entrySet());
        Collections.sort(list, (i1, i2) -> i2.getValue().compareTo(i1.getValue()));
        for (Map.Entry<Integer, Integer> aa : list) {
            sum+=aa.getValue();
            count++;
            if(sum>=arr.length/2){
                return count;
            }
        }
        return -1;
    }
}

class Solution {
    public String countAndSay(int n) {
        StringBuilder sb = new StringBuilder("1");
        StringBuilder temp = new StringBuilder();
        int sikl=2, count;
        while(sikl++<=n){
            count=1;
            for(int i=1; i<sb.length(); i++){
                if(sb.charAt(i-1)==sb.charAt(i)) count++;
                else{
                    temp.append(count).append(sb.charAt(i-1));
                    count = 1;
                }
            }
            temp.append(count).append(sb.charAt(sb.length()-1));
            sb=temp;
            temp = new StringBuilder();
        }
        return sb.toString();
    }
}

class Solution {
    public boolean isValidSudoku(char[][] board) {
        boolean case1=true, case2=true, case3=true;
        Set<Character> set1 = new HashSet<>();
        Set<Character> set2 = new HashSet<>();
        Set<Character> set3 = new HashSet<>();
        for(int i=0; i<9; i++){ 
            for(int j=0; j<9; j++){ 
                if(board[i][j] != '.' && !set1.add(board[i][j])) return false;
                if(board[j][i] != '.' && !set2.add(board[j][i])) return false;
                if(board[3*(i/3)+j/3][3*(i%3)+j%3] != '.' && 
                   !set3.add(board[3*(i/3)+j/3][3*(i%3)+j%3])) return false;
            }
            set1 = new HashSet<>();
            set2 = new HashSet<>();
            set3 = new HashSet<>();
        }
        return true;
    }
}