CareerCup

String [] strArray = new String [] {"Om", "Om","Shankar","Tripathi", "Tom", "Jerry", "Jerry"};

HashMap<String, Integer> map = new HashMap<String, Integer>();

for(String arrVal: strArray)
{
map.put(arrVal, map.containsKey(arrVal) ? map.get(arrVal)+1 : 1);
}

for (Map.Entry<String, Integer> entry : map.entrySet()) {
if(entry.getValue()>1){
String key = entry.getKey();
Object value = entry.getValue();

System.out.println(key + ":"+value);
}
}

String [] strArray = new String [] {"Om", "Om","Shankar","Tripathi", "Tom", "Jerry", "Jerry"};

HashMap<String, Integer> map = new HashMap<String, Integer>();

for(String arrVal: strArray)
{
map.put(arrVal, map.containsKey(arrVal) ? map.get(arrVal)+1 : 1);
}

for (Map.Entry<String, Integer> entry : map.entrySet()) {
if(entry.getValue()>1){
String key = entry.getKey();
Object value = entry.getValue();

System.out.println(key + ":"+value);
}
}

// ZoomBA
mset ( array_of_strings )

import java.util.HashSet;

public class NumberOfDuplicateChars {

	public static void main(String[] args) {
		String [] strArray = new String [] {"Om", "Om","Shankar","Tripathi", "Tom", "Jerry", "Jerry"};
		
		int count = 0;
		
		HashSet<String> hs = new HashSet<String>();
		
		for(String s : strArray)
		{
			if(!hs.add(s))
				count++;
		}
		
		System.out.println(strArray.length - hs.size());
		//OR
		System.out.println(count);

	}

}

So this depends on whether or not you're finding the duplicates of one substring in a longer string sentence, or finding any substring in the sentence that has duplicates and how many. This is the latter way in Python from my experience.

def dupeStrings(arr):
	counts = {}
	for each in arr:
		if arr.count(each) > 1:
			counts[each] = arr.count(each)
	return counts

Passing any array of strings will return a dictionary with the word name and the number of duplicates found.

String [] strArray = new String [] {"Om", "Om","Shankar","Tripathi", "Tom", "Jerry", "Jerry"};

HashMap<String, Integer> map = new HashMap<String, Integer>();

for(String arrVal: strArray)
{
map.put(arrVal, map.containsKey(arrVal) ? map.get(arrVal)+1 : 1);
}

for (Map.Entry<String, Integer> entry : map.entrySet()) {
if(entry.getValue()>1){
String key = entry.getKey();
Object value = entry.getValue();

System.out.println(key + ":"+value);
}
}

void CountString(vector<string> strings) {
std::map<string, int> data;
for(auto& v : strings)
{
	if(data.find(v) != data.end())
	{
		data[v] += 1;
	}
	else
	{
		data[v] = 1;
	}
 }
}

Complex: O(n)

public int getDuplicateCount(T[] arr){
		if(arr == null) return 0;
		boolean[] grid= new  boolean[arr.length] ;
		int count=0; int nullcount=0;
		for (T t : arr) {
			if(null == t){
				nullcount++; 
				continue;
			}
			int idx = t.hashCode()%arr.length;
			if(grid[idx]){
				count++;
			}else{
				grid[idx]= true;
			}
		}		
		return count;		
	}

public int getDuplicateCount(T[] arr){
		if(arr == null) return 0;
		boolean[] grid= new  boolean[arr.length] ;
		int count=0; int nullcount=0;
		for (T t : arr) {
			if(null == t){
				nullcount++; 
				continue;
			}
			int idx = t.hashCode()%arr.length;
			if(grid[idx]){
				count++;
			}else{
				grid[idx]= true;
			}
		}		
		return count;

}

package com.test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

public class Count_CharMap {
public static void main(String[] args) {
try
{
FileInputStream file = new FileInputStream("D:\\trial.txt");
DataInputStream dis = new DataInputStream(file);
BufferedReader br = new BufferedReader(new InputStreamReader(dis));
// System.out.println(br.readLine());
String Contents="";
String str="";

while ((Contents = br.readLine()) != null) {
str+=Contents;
}

char[]char_array =str.toCharArray();
System.out.println(char_array);
// int count = 0;


Map<Character,Integer> charCounter=new HashMap<Character,Integer>();
for(int i=0;i<str.length();i++)
{
System.out.print(char_array[i]);
char ch = char_array[i];
if(charCounter.containsKey(char_array[i]))
{
charCounter.put(ch, charCounter.get(ch)+1);
// count++;
}
else
{
charCounter.put(ch, 1);
// count++;
}
}

System.out.println(charCounter);
for(Character key:charCounter.keySet())
{
System.out.println(key+""+charCounter.get(key));
}
System.out.print("\n");
new File("D:/Java").mkdir();
File statText = new File("D:/Java/statsTest.txt");
FileOutputStream is = new FileOutputStream(statText);
OutputStreamWriter osw = new OutputStreamWriter(is);
Writer w = new BufferedWriter(osw);
for(Character key:charCounter.keySet())
{
w.write(key+"="+charCounter.get(key)+"\n");
w.append(System.lineSeparator());

// w.write("\n");
}
// w.write("POTATO!!!"+ new Date());
// w.write(h);
w.close();
}
catch(IOException e1){
System.out.println(e1);
}

}
}

// Written in javascript

var arr = ['ab', 'cd', 'ab', 'drj', 'jr', 'jr'];

Array.prototype.contains = function(obj){
   for(let i=0; i<this.length; i++){
      if(this[i]===obj)
         return true;
   }
   return false;
}

var dupStr = function(arr){
   let temp = [];
   for(let i=0; i<arr.length; i++){
      if(!temp.contains(arr[i]))
         temp.push(arr[i]);
   }
   console.log(arr.length - temp.length);
}

dupStr(arr);

Set<String> uniquUsers = new HashSet<String>();
        int count = 0;
        for (int i = 0; i < users.length; i++) {
            if (!uniquUsers.add(users[i]))
                count++;                         
        }

String [] strArray = new String [] {"Om", "Om","Shankar","Tripathi", "Tom", "Jerry", "Jerry"};
int counter=0;
for (int i = 0; i < strArray.length; i++) {
for (int j = i+1; j < strArray.length; j++) {
if(strArray[i].equals(strArray[j])){
counter++;
break;
}
}

}

System.out.println(counter);

String [] strArray = new String [] {"Om", "Om","Shankar","Tripathi", "Tom", "Jerry", "Jerry"};
		int counter=0;
		for (int i = 0; i < strArray.length; i++) {
			for (int j = i+1; j < strArray.length; j++) {
				if(strArray[i].equals(strArray[j])){
					counter++;
					break;
				}
			}
			
		}
		
		System.out.println(counter);