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Commit 6ec3859

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newProblems
1 parent c95fdc1 commit 6ec3859

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3 files changed

+484
-7
lines changed

3 files changed

+484
-7
lines changed

‎src/arrays/starter.java

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This file was deleted.

‎src/hashmaps/practiceProblems.java

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package hashmaps;
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import java.util.*;
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public class practiceProblems {
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public static int lengthOfLongestSubsetWithZeroSum(ArrayList<Integer> arr)
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{
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if(arr.size()==1){
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if(arr.get(0)==0){
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return 1;
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}
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else{
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return 0;
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}
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}
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int mx=0;
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int len=0;
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HashMap<Integer,Integer>mp=new HashMap<>();
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int cum=0;
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mp.put(arr.get(0),0);
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for(int i=1;i<arr.size();i++){
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cum+=arr.get(i);
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if(arr.get(i)==0 && mx==0){
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mx=1;
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}
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if(mp.containsKey(cum) || cum==0){
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if(mp.containsKey(cum)){
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len=i-mp.get(cum);
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}
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if(cum==0){
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len=i+1;
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}
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if(len>mx){
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mx=len;
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}
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}
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else{
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mp.put(cum,i);
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}
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}
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return mx;
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}
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public static void findPairsDifferenceK(int[] input, int k){
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HashMap<Integer,Integer> mp=new HashMap<>();
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for(int i=0;i<input.length;i++){
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if(mp.containsKey(input[i])){
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mp.put(input[i],mp.get(input[i])+1);
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}
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else{
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mp.put(input[i],1);
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}
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}
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int count1=0;
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int count2=0;
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for(int i=0;i<input.length;i++){
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if(k==0){
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count1=mp.get(input[i]);
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int total=((count1-1)*count1)/2;
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while(total-->0){
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System.out.println(input[i]+" "+input[i]);
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}
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}
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else{
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if(mp.containsKey(input[i]-k) ){
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count1=mp.get(input[i]);
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count2=mp.get(input[i]-k);
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int total=count1*count2;
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while(total-->0){
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System.out.println((input[i]-k)+" "+input[i]);
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}
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}
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if(mp.containsKey(input[i]+k)){
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count1=mp.get(input[i]);
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count2=mp.get(input[i]+k);
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int total=count1*count2;
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while(total-->0){
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System.out.println(input[i]+" "+(input[i]+k));
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}
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}
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}
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mp.put(input[i],0);
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}
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}
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public static ArrayList<Integer> longestConsecutiveIncreasingSequence(int[] arr) {
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int n=arr.length;
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HashMap<Integer,Boolean> mp=new HashMap<>();
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HashMap<Integer,Integer>pos=new HashMap<>();
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for(int i=0;i<n;i++){
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mp.put(arr[i],true);
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pos.put(arr[i],i);
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}
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int mx=1,start=0;
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for(int i=0;i<n;i++){
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int len=0;
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int val=arr[i];
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int curr=arr[i];
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int index=i;
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while(mp.containsKey(val) && mp.get(val)==true){
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len++;
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mp.put(val,false);
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val+=1;
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}
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val=curr-1;
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while(mp.containsKey(val) && mp.get(val)==true){
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len++;
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// curr=val;
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mp.put(val,false);
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index= pos.get(val);
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val-=1;
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// index-=1;
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}
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if(mx<len){
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mx=len;
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start=index;
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}
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else if(mx==len){
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if(index<start){
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start=index;
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}
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}
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// mp.put(arr[i],false);
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}
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ArrayList<Integer> out=new ArrayList<>();
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out.add(arr[start]);
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int value=arr[start];
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mx--;
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while(mx!=0)
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{
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value+=1;
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out.add(value);
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mx--;
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}
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return out;
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}
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// remove all duplicates
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public static String uniqueChar(String str){
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HashMap<Character,Boolean> mp=new HashMap<>();
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for(int i=0;i<str.length();i++){
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mp.put(str.charAt(i),true);
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}
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String ans="";
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for(int i=0;i<str.length();i++){
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if(mp.get(str.charAt(i))==true){
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ans+=str.charAt(i);
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mp.put(str.charAt(i),false);
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}
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}
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return ans;
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}
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public static void PairSumToZERO(int[] arr, int size) {
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HashMap<Integer,Integer>mp=new HashMap<>();
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int sum=0;
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for(int i=0;i<size;i++){
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if(mp.containsKey(sum-arr[i])){
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int count=mp.get(sum-arr[i]);
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for(int j=0;j<count;j++){
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if((sum-arr[i])<arr[i]){
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System.out.println((sum-arr[i])+" "+arr[i]);
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}
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else{
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System.out.println(arr[i]+" "+(sum-arr[i]));
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}
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}
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}
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if(mp.containsKey(arr[i])){
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mp.put(arr[i],mp.get(arr[i])+1);
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}
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else{
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mp.put(arr[i],1);
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}
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}
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}
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public static void intersection(int[] arr1, int[] arr2){
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HashMap<Integer,Integer> mp=new HashMap<>();
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for(int i:arr1){
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if(mp.containsKey(i)){
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mp.put(i,mp.get(i)+1);
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}
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else
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mp.put(i,1);
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}
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for(int i:arr2){
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if(mp.containsKey(i)){
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if(mp.get(i)>0){
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System.out.println(i);
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}
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mp.put(i,mp.get(i)-1);
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// mp.put(i,false);
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}
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}
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}
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public static int maxFrequencyNumber(int[] arr){
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HashMap<Integer,Integer> mp=new HashMap<>();
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int countmax=Integer.MIN_VALUE;
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int ans=-1;
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for(int i=0;i<arr.length;i++){
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if(mp.containsKey(arr[i])){
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int val=mp.get(arr[i]);
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mp.put(arr[i],val+1);
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}
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else{
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mp.put(arr[i],1);
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}
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}
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for( int str:arr){
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if(mp.get(str)>countmax){
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ans=str;
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countmax=mp.get(str);
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}
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}
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return ans;
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}
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}

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