Description:
Find out duplicate characters in a string, and calculate the count of repetition.
Code:
package com.techonol.algos; import java.util.HashMap; import java.util.Map; import java.util.Set; public class DuplicateCharsInString { public void findDuplicateChars(String str) { Map<Character, Integer> dupMap = new HashMap<Character, Integer>(); char[] chrs = str.toCharArray(); for (Character ch : chrs) { if (dupMap.containsKey(ch)) { dupMap.put(ch, dupMap.get(ch) + 1); } else { dupMap.put(ch, 1); } } Set<Character> keys = dupMap.keySet(); for (Character ch : keys) { if (dupMap.get(ch) > 1) { System.out.println(ch + "--->" + dupMap.get(ch)); } } } public static void main(String a[]) { DuplicateCharsInString dcs = new DuplicateCharsInString(); dcs.findDuplicateChars("Techonol"); } }
Output:
o--->2