import java.util.StringJoiner; class Solution { public String reverseWords(String s) { String[] ch = s.split(" "); int i =0,j=ch.length/2; while(i<j){ String temp = ch[i]; ch[i] = ch[ch.length-i-1]; ch[ch.length-i-1] = temp; i++; } StringJoiner sJoiner = new StringJoiner(" "); for(int k =0;k<ch.length;k++){ if(!ch[k].equals("")) sJoiner.add(ch[k]); } return sJoiner.toString().trim(); } } 

class Solution { public int romanToInt(String s) { HashMap<Character,Integer> map =new HashMap<>(); map.put('I',1); map.put('V',5); map.put('X',10); map.put('L',50); map.put('C',100); map.put('D',500); map.put('M',1000); int integerValue = 0; int i = s.length()-1; while(i>0){ if(s.charAt(i)=='V' && s.charAt(i-1)=='I'){ integerValue+=4; i=i-2; } else if(s.charAt(i)=='X' && s.charAt(i-1)=='I'){ integerValue+=9; i = i-2; } else if(s.charAt(i)=='L' && s.charAt(i-1)=='X'){ integerValue+=40; i = i-2; } else if(s.charAt(i)=='C' && s.charAt(i-1)=='X'){ integerValue+=90; i = i-2; } else if(s.charAt(i)=='D' && s.charAt(i-1)=='C'){ integerValue+=400; i = i-2; } else if(s.charAt(i)=='M' && s.charAt(i-1)=='C'){ integerValue+=900; i = i-2; } else{ integerValue+=map.get(s.charAt(i)); i--; } } if(i==0) integerValue+=map.get(s.charAt(i)); return integerValue; } } 

/*package whatever //do not write package name here */ import java.io.*; import java.util.*; class GFG { public static void main (String[] args) { List<String> sentence= new ArrayList<>(); List<String> queries = new ArrayList<>(); sentence.add("bob and alice like to text each other"); sentence.add("bob does not like to ski but does not like to fall"); sentence.add("Alice likes to ski"); queries.add("bob alice"); queries.add("alice"); queries.add("like"); queries.add("non occurance"); System.out.println(get(sentence,queries)); } public static List<List<Integer>> get(List<String> sentence, List<String> q){ List<List<Integer>> list = new ArrayList<>(); for(int j =0;j<q.size();j++){ List<Integer> res = new ArrayList<>(); String str[] = q.get(j).split(" "); for(int i =0;i<sentence.size();i++){ String sen = sentence.get(i); boolean present = true; for(String s : str){ if(!sen.contains(s)){ present = false; break; } } if(present){ res.add(i);// sentence index that had s got added } } if(res.isEmpty()){ List<Integer> temp = new ArrayList<>(); temp.add(-1); list.add(temp); } else list.add(res); } return list; } } 

class Solution { public String longestPalindrome(String s) { //the lcs approach won't work here //we will have to use traditional approach of two loops for finding longest //palindromic subsequence int start=0; int length = 1; int n = s.length(); if(n<2) return s; for(int i =0;i<n;i++){ int low = i-1; int high = i+1; //below will check till how long the index values of high are equal to current index //which will be palindrome obviously while(high < n && s.charAt(high) == s.charAt(i)){ high++; } //same logic as above for low index while(low>=0 && s.charAt(low) == s.charAt(i)){ low--; } //finally low and high together while(low >=0 && high<n && s.charAt(low)== s.charAt(high)){ low--; high++; } int len = high-low -1; if(len> length){ length = len; start = low+1; } } //if we were to return length of the logest palindromic substring we could have returned 'length'; return s.substring(start,start+length); } } 

class Solution { public int compareVersion(String version1, String version2) { version1 = version1+".0"; version2 = version2+".0"; String[] a = version1.split("\\."); String[] b = version2.split("\\."); int exL = Math.abs(a.length - b.length); if(a.length > b.length){ char c = '0'; while(exL-->0){ version2 = version2+"."+c; } } else { char c = '0'; while(exL-->0){ version1 = version1+"."+c; } } /// now two strings are equal a= version1.split("\\."); b = version2.split("\\."); System.out.println(a.length + " "+ b.length); for(int i =0;i<a.length;i++){ int p = Integer.parseInt(a[i]); int q = Integer.parseInt(b[i]); if(p > q) return 1; if(p < q) return -1; } return 0; } } 

class Solution { List<List<String>> getPartitions(String s) { // add logic here  List<List<String>> list = new ArrayList<>(); f(s,0,new ArrayList<>(),list); return list; } public void f(String s, int index, List<String> l,List<List<String>> list){ if(index>=s.length()){ list.add(new ArrayList<>(l)); return; } for(int i = index;i<s.length();i++){ if(!isP(s,index,i)) continue; l.add(s.substring(index,i+1)); f(s,i+1,l,list); l.remove(l.size()-1); } } public boolean isP(String s, int i,int e){ while(i<=e){ if(s.charAt(i++)!=s.charAt(e--)) return false; } return true; } }