finding all subsets array question

Author: sathishmepco

Collections/.gitignore

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+/bin/

Collections/src/com/cdac/collections/map/HashMapDemo.java

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+package com.cdac.collections.map;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Set;
+
+public class HashMapDemo {
+	public static void main(String[] args) {
+		HashMap<Integer, String> map = new HashMap<>();
+		//ADD
+		map.put(1, "One");
+		map.put(2, "Two");
+		map.put(3, "Three");
+		map.put(null, null);
+		map.put(null, "Hello");
+		map.put(4, "Hello");
+		//only one null key allowed
+		//duplicate keys are not allowed
+		
+		//CHECK OR CONTAIN
+		boolean keyAvailable = map.containsKey(11);
+		System.out.println("Is Key 11 is available :: "+keyAvailable);
+		keyAvailable = map.containsKey(1);
+		System.out.println("Is Key 1 is available :: "+keyAvailable);
+		boolean valueAvailable = map.containsValue("Five");
+		System.out.println("Is value Five available :: "+valueAvailable);
+		
+		//READ OR ITERATE
+		String value = map.get(2);
+		System.out.println("Value for the Key 2 is :: "+value);
+		value = map.get(1);
+		System.out.println("Value for the Key 1 is :: "+value);
+		
+		//SIZE AND ISEMPTY
+		int mapSize = map.size();
+		boolean isMapEmpty = map.isEmpty();
+		System.out.println("Map Size is :: "+mapSize);
+		System.out.println("Is the Map is empty :: "+isMapEmpty);
+		
+		//READ ALL THE KEYS
+		System.out.println("Read All the Keys - ");
+		Set<Integer> keySet = map.keySet();
+		Iterator<Integer> keyIterator = keySet.iterator();
+		while(keyIterator.hasNext()){
+			Integer key = keyIterator.next();
+			System.out.println(key);
+		}
+		
+		//READ ALL THE VALUES
+		System.out.println("Read all the values - ");
+		List<String> listValues = (List<String>) map.values();
+		for(String val : listValues){
+			System.out.println(val);
+		}
+		
+		
+	}
+}

FileIO/.gitignore

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+/bin/

Generics/.gitignore

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+/bin/

InterviewPrograms/.gitignore

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+/bin/

InterviewPrograms/src/com/java/array/FindDuplicates.java

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+package com.java.array;
+
+import java.util.Arrays;
+import java.util.HashSet;
+
+//MAXIMUM SCORE IS 100
+public class FindDuplicates {
+	public static void main(String[] args) {
+		HashSet<Integer> set = new HashSet<>();
+		int array[] = {4,2,4,5,2,3,1,2,3};
+		for(int i =0;i<array.length;i++){
+			if(array[Math.abs(array[i])] > 0)
+				array[Math.abs(array[i])] = -array[Math.abs(array[i])];
+			else{
+				set.add(Math.abs(array[i]));
+			}
+		}
+		System.out.println("No of duplicate elements are :: "+set.size());
+	}
+}

InterviewPrograms/src/com/java/array/FindUniqueElt.java

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+package com.java.array;
+
+/*
+ In the given array, only one element is not repeated 
+ all other elements are repeated exactly 2 times. 
+ Find the element which occured only one time. 
+ */
+public class FindUniqueElt {
+	public static void main(String[] args) {
+		int array[] = { 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5};
+		int output = array[0];
+		for(int i=1;i<array.length;i++)
+			output ^= array[i];
+		System.out.println(output);
+	}
+}

InterviewPrograms/src/com/java/array/FindingAllSubsets.java

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+package com.java.array;
+
+public class FindingAllSubsets {
+	
+	public static void main(String[] args) {
+		//solution 1 follows bitwise approach
+//		solution1();
+		
+		//solution 2 follows recursion approach
+		solution2();
+	}
+
+	public static void solution1() {
+		char set[] = {'a','b','c','d'};
+		int n = set.length;
+		for (int i = 0; i < (1 << n); i++) {
+			System.out.print("{ ");
+			for (int j = 0; j < n; j++){
+				if ((i & (1 << j)) > 0)
+					System.out.print(set[j] + " ");
+			}
+			System.out.println("}");
+		}
+	}
+	
+	public static void solution2(){
+		int array[] = {10,20,30,40,50};
+		int visited[] = new int[array.length];
+		traverse(array, visited,0);
+	}
+	
+	public static void traverse(int array[],int visited[],int curIndex){
+		System.out.print("\n{ ");
+		for(int i=0;i<visited.length;i++)
+			if(visited[i] == 1)
+				System.out.print(array[i]+" ");
+		System.out.print("}");
+		
+		for(int j=curIndex;j<array.length;j++){
+			visited[j] = 1;
+			traverse(array, visited,j+1);
+			visited[j] = 0;
+		}
+	}
+}
+
+/*
+ * 
+ * Input: S = {a, b, c, d} Output: {}, {a} , {b}, {c}, {d}, {a,b}, {a,c}, {a,d},
+ * {b,c}, {b,d}, {c,d}, {a,b,c}, {a,b,d}, {a,c,d}, {b,c,d}, {a,b,c,d}
+ * 
+ */

Networking/.gitignore

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+/bin/

Threads/.gitignore

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+/bin/