translation: Add Python and Java code for EN version (#1345)

* Add the intial translation of code of all the languages

* test

* revert

* Remove

* Add Python and Java code for EN version

en/codes/java/chapter_heap/heap.java

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+/**
+ * File: heap.java
+ * Created Time: 2023-01-07
+ * Author: krahets (krahets@163.com)
+ */
+
+package chapter_heap;
+
+import utils.*;
+import java.util.*;
+
+public class heap {
+    public static void testPush(Queue<Integer> heap, int val) {
+        heap.offer(val); // Push the element into heap
+        System.out.format("\nAfter element %d is added to the heap\n", val);
+        PrintUtil.printHeap(heap);
+    }
+
+    public static void testPop(Queue<Integer> heap) {
+        int val = heap.poll(); // Pop the element at the heap top
+        System.out.format("\nAfter the top element %d is removed from the heap\n", val);
+        PrintUtil.printHeap(heap);
+    }
+
+    public static void main(String[] args) {
+        /* Initialize the heap */
+        // Initialize min-heap
+        Queue<Integer> minHeap = new PriorityQueue<>();
+        // Initialize the max-heap (using lambda expression to modify Comparator if necessary)
+        Queue<Integer> maxHeap = new PriorityQueue<>((a, b) -> b - a);
+
+        System.out.println("\nThe following test case is for max-heap");
+
+        /* Push the element into heap */
+        testPush(maxHeap, 1);
+        testPush(maxHeap, 3);
+        testPush(maxHeap, 2);
+        testPush(maxHeap, 5);
+        testPush(maxHeap, 4);
+
+        /* Access heap top element */
+        int peek = maxHeap.peek();
+        System.out.format("\nTop element of the heap is %d\n", peek);
+
+        /* Pop the element at the heap top */
+        testPop(maxHeap);
+        testPop(maxHeap);
+        testPop(maxHeap);
+        testPop(maxHeap);
+        testPop(maxHeap);
+
+        /* Get heap size */
+        int size = maxHeap.size();
+        System.out.format("\nNumber of elements in the heap is %d\n", size);
+
+        /* Determine if heap is empty */
+        boolean isEmpty = maxHeap.isEmpty();
+        System.out.format("\nIs the heap empty %b\n", isEmpty);
+
+        /* Enter list and build heap */
+        // Time complexity is O(n), not O(nlogn)
+        minHeap = new PriorityQueue<>(Arrays.asList(1, 3, 2, 5, 4));
+        System.out.println("\nEnter list and build min-heap");
+        PrintUtil.printHeap(minHeap);
+    }
+}

en/codes/java/chapter_heap/my_heap.java

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+/**
+ * File: my_heap.java
+ * Created Time: 2023-01-07
+ * Author: krahets (krahets@163.com)
+ */
+
+package chapter_heap;
+
+import utils.*;
+import java.util.*;
+
+/* Max-heap */
+class MaxHeap {
+    // Use list instead of array to avoid the need for resizing
+    private List<Integer> maxHeap;
+
+    /* Constructor, build heap based on input list */
+    public MaxHeap(List<Integer> nums) {
+        // Add all list elements into the heap
+        maxHeap = new ArrayList<>(nums);
+        // Heapify all nodes except leaves
+        for (int i = parent(size() - 1); i >= 0; i--) {
+            siftDown(i);
+        }
+    }
+
+    /* Get index of left child node */
+    private int left(int i) {
+        return 2 * i + 1;
+    }
+
+    /* Get index of right child node */
+    private int right(int i) {
+        return 2 * i + 2;
+    }
+
+    /* Get index of parent node */
+    private int parent(int i) {
+        return (i - 1) / 2; // Integer division down
+    }
+
+    /* Swap elements */
+    private void swap(int i, int j) {
+        int tmp = maxHeap.get(i);
+        maxHeap.set(i, maxHeap.get(j));
+        maxHeap.set(j, tmp);
+    }
+
+    /* Get heap size */
+    public int size() {
+        return maxHeap.size();
+    }
+
+    /* Determine if heap is empty */
+    public boolean isEmpty() {
+        return size() == 0;
+    }
+
+    /* Access heap top element */
+    public int peek() {
+        return maxHeap.get(0);
+    }
+
+    /* Push the element into heap */
+    public void push(int val) {
+        // Add node
+        maxHeap.add(val);
+        // Heapify from bottom to top
+        siftUp(size() - 1);
+    }
+
+    /* Start heapifying node i, from bottom to top */
+    private void siftUp(int i) {
+        while (true) {
+            // Get parent node of node i
+            int p = parent(i);
+            // When "crossing the root node" or "node does not need repair", end heapification
+            if (p < 0 || maxHeap.get(i) <= maxHeap.get(p))
+                break;
+            // Swap two nodes
+            swap(i, p);
+            // Loop upwards heapification
+            i = p;
+        }
+    }
+
+    /* Element exits heap */
+    public int pop() {
+        // Empty handling
+        if (isEmpty())
+            throw new IndexOutOfBoundsException();
+        // Swap the root node with the rightmost leaf node (swap the first element with the last element)
+        swap(0, size() - 1);
+        // Remove node
+        int val = maxHeap.remove(size() - 1);
+        // Heapify from top to bottom
+        siftDown(0);
+        // Return heap top element
+        return val;
+    }
+
+    /* Start heapifying node i, from top to bottom */
+    private void siftDown(int i) {
+        while (true) {
+            // Determine the largest node among i, l, r, noted as ma
+            int l = left(i), r = right(i), ma = i;
+            if (l < size() && maxHeap.get(l) > maxHeap.get(ma))
+                ma = l;
+            if (r < size() && maxHeap.get(r) > maxHeap.get(ma))
+                ma = r;
+            // If node i is the largest or indices l, r are out of bounds, no further heapification needed, break
+            if (ma == i)
+                break;
+            // Swap two nodes
+            swap(i, ma);
+            // Loop downwards heapification
+            i = ma;
+        }
+    }
+
+    /* Print heap (binary tree) */
+    public void print() {
+        Queue<Integer> queue = new PriorityQueue<>((a, b) -> { return b - a; });
+        queue.addAll(maxHeap);
+        PrintUtil.printHeap(queue);
+    }
+}
+
+public class my_heap {
+    public static void main(String[] args) {
+        /* Initialize max-heap */
+        MaxHeap maxHeap = new MaxHeap(Arrays.asList(9, 8, 6, 6, 7, 5, 2, 1, 4, 3, 6, 2));
+        System.out.println("\nEnter list and build heap");
+        maxHeap.print();
+
+        /* Access heap top element */
+        int peek = maxHeap.peek();
+        System.out.format("\nTop element of the heap is %d\n", peek);
+
+        /* Push the element into heap */
+        int val = 7;
+        maxHeap.push(val);
+        System.out.format("\nAfter element %d is added to the heap\n", val);
+        maxHeap.print();
+
+        /* Pop the element at the heap top */
+        peek = maxHeap.pop();
+        System.out.format("\nAfter the top element %d is removed from the heap\n", peek);
+        maxHeap.print();
+
+        /* Get heap size */
+        int size = maxHeap.size();
+        System.out.format("\nNumber of elements in the heap is %d\n", size);
+
+        /* Determine if heap is empty */
+        boolean isEmpty = maxHeap.isEmpty();
+        System.out.format("\nIs the heap empty %b\n", isEmpty);
+    }
+}

en/codes/java/chapter_heap/top_k.java

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+/**
+ * File: top_k.java
+ * Created Time: 2023-06-12
+ * Author: krahets (krahets@163.com)
+ */
+
+package chapter_heap;
+
+import utils.*;
+import java.util.*;
+
+public class top_k {
+    /* Using heap to find the largest k elements in an array */
+    static Queue<Integer> topKHeap(int[] nums, int k) {
+        // Initialize min-heap
+        Queue<Integer> heap = new PriorityQueue<Integer>();
+        // Enter the first k elements of the array into the heap
+        for (int i = 0; i < k; i++) {
+            heap.offer(nums[i]);
+        }
+        // From the k+1th element, keep the heap length as k
+        for (int i = k; i < nums.length; i++) {
+            // If the current element is larger than the heap top element, remove the heap top element and enter the current element into the heap
+            if (nums[i] > heap.peek()) {
+                heap.poll();
+                heap.offer(nums[i]);
+            }
+        }
+        return heap;
+    }
+
+    public static void main(String[] args) {
+        int[] nums = { 1, 7, 6, 3, 2 };
+        int k = 3;
+
+        Queue<Integer> res = topKHeap(nums, k);
+        System.out.println("The largest " + k + " elements are");
+        PrintUtil.printHeap(res);
+    }
+}