anagram from a string

a stand alone java program to create all the possible combination from a string

Author: joydeep1982

Anagram.java

@@ -0,0 +1,61 @@
+package org.hacker.rank;
+
+import java.util.Map;
+import java.util.TreeMap;
+
+public class Anagram {
+	
+	public static void main(String[] args) {
+		String input = "abc";
+		
+		// Create map to find the unique aphabets and count
+		Map<Character, Integer> dataMap = new TreeMap<>();
+		for(int i = 0; i <input.length(); i++) {
+			if (dataMap.containsKey(input.charAt(i))) {
+				dataMap.put(input.charAt(i), dataMap.get(input.charAt(i)) + 1);
+			}
+			else {
+				dataMap.put(input.charAt(i), 1);
+			}
+		}
+		
+		// character array to hold the characters
+		char[] chars = new char[dataMap.size()];
+
+		// integer array to hold the count of the character
+		int[] count = new int[dataMap.size()];
+		
+		int index = 0;
+		
+		for(Map.Entry<Character, Integer> entry : dataMap.entrySet()) {
+			chars[index] = entry.getKey();
+			count[index] = entry.getValue();
+			index++;
+		}
+		
+		char[] container = new char[input.length()];
+		anagram(chars, count, container, 0);
+	}
+
+	// recursively find the anagram
+	public static void anagram(char[] chars, int[] count, char[] result, int level){
+		if (level == result.length) {
+			print(result);
+			return;
+		}
+		for (int i = 0; i < count.length; i++) {
+			if(count[i] == 0) continue;
+			count[i]--;
+			result[level] = chars[i];
+			anagram(chars, count, result, level + 1);
+			count[i]++;
+		}
+	}
+	
+	public static void print(char[] ch) {
+		for(char c : ch) {
+			System.out.print(c);
+		}
+		System.out.println("");
+	}
+}