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);
        }

        List<List<String>> list = new ArrayList<>();
        List<String> temp = new ArrayList<>(); temp.add("Table");
        for (String s: set)
            temp.add(s);
        list.add(temp);
        for (Map.Entry<Integer, TreeMap<String, Integer>> entry: map.entrySet()){
            temp = new ArrayList<>();
            temp.add(String.valueOf(entry.getKey()));
            for (String s : set)
                temp.add(String.valueOf(entry.getValue().getOrDefault(s, 0)));
            list.add(temp);
        }
        return list;
    }
}

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 int percentageLetter(String s, char letter) {
        int count=0;
        for(char ch: s.toCharArray())
            if(ch==letter) count++;
        return count*100/s.length();
    }
}

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 boolean divisorGame(int n) {
        return n%2==0;
    }
}

class Solution {
    public void merge(int[] nums1, int m, int[] nums2, int n) {
        for(int i=nums1.length-1; i>=0; i--){
            if(m>0 && n>0){
                if(nums1[m-1]>nums2[n-1]){
                    nums1[i]=nums1[m-1];
                    m--;
                }else{
                    nums1[i]=nums2[n-1];
                    n--;
                }
            }
        }
        for(int i=n-1; i>=0; i--){
            nums1[i]=nums2[i];
        }
        
    }
}

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 boolean isSubsequence(String s, String t) {
        if(s.length()==0) return true;
        int is=0, it=0;
        while(it<t.length()){
            if(s.charAt(is)==t.charAt(it)){
                is++;
                if(is==s.length()) return true;
            }
            it++;
        }
        return false;
    }
}

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 double findMedianSortedArrays(int[] nums1, int[] nums2) {
        int l1=nums1.length, l2=nums2.length, l=l1+l2;
        int num[] = new int[l], i=0, j=0;
        for(; i<l1 || j<l2; ){
            if(i<l1 && j<l2){
                if(nums1[i]>nums2[j])
                    num[i+j]=nums2[j++];
                else
                    num[i+j]=nums1[i++];
            }else if(i<l1)
                num[i+j]=nums1[i++];
            else
                num[i+j]=nums2[j++];
        }
        return l%2==0 ? (num[l/2-1]+num[l/2])/2.0 : (double)num[l/2];
    }
}

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 String longestCommonPrefix(String[] strs) {
        String s=strs[0];
        int l=s.length(), count=0;
        while(l>0){
            count=0;
            for(String str:strs){
                if(str.startsWith(s.substring(0, l))) count++;
            }
            if(count==strs.length) return s.substring(0, l);
            l--;
        }
        return "";
    }
}

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 Solution {
    public ListNode mergeKLists(ListNode[] lists) {
        if(lists.length==0) return null;
        ListNode res=lists[0];        
        for(int i=1; i<lists.length; i++)
            res=merge(res, lists[i]);
        return res;
    }
    public ListNode merge(ListNode res, ListNode list){
        ListNode l1=new ListNode(0);
        ListNode head=l1;
        while(res!=null && list!=null){
            if(res.val<list.val){
                l1.next=res;
                res=res.next;
            }else{
                l1.next=list;
                list=list.next;
            }
            l1=l1.next;
        }
        while(res!=null){
            l1.next=res;
            res=res.next;
            l1=l1.next;
        }
        while(list!=null){
            l1.next=list;
            list=list.next;
            l1=l1.next;
        }
        return head.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;
    }
}