most frequent k words

Author: dheeraj9198

src/heap/KMostFrequent.java

@@ -0,0 +1,117 @@
+package heap;
+
+import java.util.HashMap;
+
+/**
+ * Created by dheeraj on 7/8/2016.
+ */
+public class KMostFrequent {
+
+    static Data[] datas = new Data[5];
+    static int size;
+
+    private static void addToHeap(Data data) {
+        if (size < datas.length) {
+            datas[size] = data;
+            data.heapIndex = size;
+            size++;
+            if (size == datas.length) {
+                buildHeap();
+            }
+        } else if (datas[0].count < data.count) {
+            datas[0].heapIndex = -1;
+            datas[0] = data;
+            datas[0].heapIndex = 0;
+            heapify(0);
+        }
+    }
+
+    private static void buildHeap() {
+        int p = getParent(datas.length - 1);
+        for (int k = p; p >= 0; p--) {
+            heapify(k);
+        }
+    }
+
+    private static void heapify(int k) {
+        int min = k;
+        int l = getLeft(k);
+        int r = getRight(k);
+
+        if (l <= datas.length - 1 && datas[l].count < datas[k].count) {
+            min = l;
+        }
+
+        if (r <= datas.length - 1 && datas[r].count < datas[min].count) {
+            min = r;
+        }
+
+        if (min != k) {
+            Data data = datas[min];
+            datas[k] = data;
+            datas[k].heapIndex = k;
+            datas[min] = datas[k];
+            datas[min].heapIndex = min;
+            heapify(min);
+        }
+    }
+
+
+    private static int getParent(int child) {
+        return (child - 1) / 2;
+    }
+
+    private static int getRight(int p) {
+        return 2 * p + 2;
+    }
+
+    private static int getLeft(int p) {
+        return 2 * p + 1;
+    }
+
+
+    static class Data {
+        int count;
+        String word;
+        int heapIndex;
+
+        public Data(String word, int count, int heapIndex) {
+            this.count = count;
+            this.word = word;
+            this.heapIndex = -1;
+        }
+    }
+
+    private static HashMap<String, Data> wordCountMap = new HashMap<String, Data>();
+
+    private static void addWord(String word) {
+        Data data = wordCountMap.get(word);
+        if (data == null) {
+            data = new Data(word, 1, -1);
+            wordCountMap.put(word, data);
+            addToHeap(data);
+        } else {
+            data.count++;
+            if (data.heapIndex == -1) {
+                addToHeap(data);
+            } else {
+                heapify(data.heapIndex);
+            }
+        }
+    }
+
+    public static void main(String[] strings) {
+        String s = "Welcome to the world of Geeks " +
+                "This portal has been created to provide well written well thought and well explained " +
+                "solutions for selected questions If you like Geeks for Geeks and would like to contribute " +
+                "here is your chance You can write article and mail your article to contribute at " +
+                "geeksforgeeks org See your article appearing on the Geeks for Geeks main page and help" +
+                "thousands of other Geeks";
+        String[] strings1 = s.split(" ");
+        for (String s1 : strings1) {
+            addWord(s1);
+        }
+        System.out.println();
+    }
+
+}