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_searching/binary_search.java

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+/**
+ * File: binary_search.java
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+package chapter_searching;
+
+public class binary_search {
+    /* Binary search (double closed interval) */
+    static int binarySearch(int[] nums, int target) {
+        // Initialize double closed interval [0, n-1], i.e., i, j point to the first element and last element of the array respectively
+        int i = 0, j = nums.length - 1;
+        // Loop until the search interval is empty (when i > j, it is empty)
+        while (i <= j) {
+            int m = i + (j - i) / 2; // Calculate midpoint index m
+            if (nums[m] < target) // This situation indicates that target is in the interval [m+1, j]
+                i = m + 1;
+            else if (nums[m] > target) // This situation indicates that target is in the interval [i, m-1]
+                j = m - 1;
+            else // Found the target element, thus return its index
+                return m;
+        }
+        // Did not find the target element, thus return -1
+        return -1;
+    }
+
+    /* Binary search (left closed right open interval) */
+    static int binarySearchLCRO(int[] nums, int target) {
+        // Initialize left closed right open interval [0, n), i.e., i, j point to the first element and the last element +1 of the array respectively
+        int i = 0, j = nums.length;
+        // Loop until the search interval is empty (when i = j, it is empty)
+        while (i < j) {
+            int m = i + (j - i) / 2; // Calculate midpoint index m
+            if (nums[m] < target) // This situation indicates that target is in the interval [m+1, j)
+                i = m + 1;
+            else if (nums[m] > target) // This situation indicates that target is in the interval [i, m)
+                j = m;
+            else // Found the target element, thus return its index
+                return m;
+        }
+        // Did not find the target element, thus return -1
+        return -1;
+    }
+
+    public static void main(String[] args) {
+        int target = 6;
+        int[] nums = { 1, 3, 6, 8, 12, 15, 23, 26, 31, 35 };
+
+        /* Binary search (double closed interval) */
+        int index = binarySearch(nums, target);
+        System.out.println("Index of target element 6 =" + index);
+
+        /* Binary search (left closed right open interval) */
+        index = binarySearchLCRO(nums, target);
+        System.out.println("Index of target element 6 =" + index);
+    }
+}

en/codes/java/chapter_searching/binary_search_edge.java

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+/**
+ * File: binary_search_edge.java
+ * Created Time: 2023-08-04
+ * Author: krahets (krahets@163.com)
+ */
+
+package chapter_searching;
+
+public class binary_search_edge {
+    /* Binary search for the leftmost target */
+    static int binarySearchLeftEdge(int[] nums, int target) {
+        // Equivalent to finding the insertion point of target
+        int i = binary_search_insertion.binarySearchInsertion(nums, target);
+        // Did not find target, thus return -1
+        if (i == nums.length || nums[i] != target) {
+            return -1;
+        }
+        // Found target, return index i
+        return i;
+    }
+
+    /* Binary search for the rightmost target */
+    static int binarySearchRightEdge(int[] nums, int target) {
+        // Convert to finding the leftmost target + 1
+        int i = binary_search_insertion.binarySearchInsertion(nums, target + 1);
+        // j points to the rightmost target, i points to the first element greater than target
+        int j = i - 1;
+        // Did not find target, thus return -1
+        if (j == -1 || nums[j] != target) {
+            return -1;
+        }
+        // Found target, return index j
+        return j;
+    }
+
+    public static void main(String[] args) {
+        // Array with duplicate elements
+        int[] nums = { 1, 3, 6, 6, 6, 6, 6, 10, 12, 15 };
+        System.out.println("\nArray nums = " + java.util.Arrays.toString(nums));
+
+        // Binary search for left and right boundaries
+        for (int target : new int[] { 6, 7 }) {
+            int index = binarySearchLeftEdge(nums, target);
+            System.out.println("The leftmost index of element " + target + " is " + index);
+            index = binarySearchRightEdge(nums, target);
+            System.out.println("The rightmost index of element " + target + " is " + index);
+        }
+    }
+}

en/codes/java/chapter_searching/binary_search_insertion.java

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+/**
+ * File: binary_search_insertion.java
+ * Created Time: 2023-08-04
+ * Author: krahets (krahets@163.com)
+ */
+
+package chapter_searching;
+
+class binary_search_insertion {
+    /* Binary search for insertion point (no duplicate elements) */
+    static int binarySearchInsertionSimple(int[] nums, int target) {
+        int i = 0, j = nums.length - 1; // Initialize double closed interval [0, n-1]
+        while (i <= j) {
+            int m = i + (j - i) / 2; // Calculate midpoint index m
+            if (nums[m] < target) {
+                i = m + 1; // Target is in interval [m+1, j]
+            } else if (nums[m] > target) {
+                j = m - 1; // Target is in interval [i, m-1]
+            } else {
+                return m; // Found target, return insertion point m
+            }
+        }
+        // Did not find target, return insertion point i
+        return i;
+    }
+
+    /* Binary search for insertion point (with duplicate elements) */
+    static int binarySearchInsertion(int[] nums, int target) {
+        int i = 0, j = nums.length - 1; // Initialize double closed interval [0, n-1]
+        while (i <= j) {
+            int m = i + (j - i) / 2; // Calculate midpoint index m
+            if (nums[m] < target) {
+                i = m + 1; // Target is in interval [m+1, j]
+            } else if (nums[m] > target) {
+                j = m - 1; // Target is in interval [i, m-1]
+            } else {
+                j = m - 1; // First element less than target is in interval [i, m-1]
+            }
+        }
+        // Return insertion point i
+        return i;
+    }
+
+    public static void main(String[] args) {
+        // Array without duplicate elements
+        int[] nums = { 1, 3, 6, 8, 12, 15, 23, 26, 31, 35 };
+        System.out.println("\nArray nums = " + java.util.Arrays.toString(nums));
+        // Binary search for insertion point
+        for (int target : new int[] { 6, 9 }) {
+            int index = binarySearchInsertionSimple(nums, target);
+            System.out.println("The insertion point index for element " + target + " is " + index);
+        }
+
+        // Array with duplicate elements
+        nums = new int[] { 1, 3, 6, 6, 6, 6, 6, 10, 12, 15 };
+        System.out.println("\nArray nums = " + java.util.Arrays.toString(nums));
+        // Binary search for insertion point
+        for (int target : new int[] { 2, 6, 20 }) {
+            int index = binarySearchInsertion(nums, target);
+            System.out.println("The insertion point index for element " + target + " is " + index);
+        }
+    }
+}

en/codes/java/chapter_searching/hashing_search.java

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+/**
+ * File: hashing_search.java
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+package chapter_searching;
+
+import utils.*;
+import java.util.*;
+
+public class hashing_search {
+    /* Hash search (array) */
+    static int hashingSearchArray(Map<Integer, Integer> map, int target) {
+        // Hash table's key: target element, value: index
+        // If the hash table does not contain this key, return -1
+        return map.getOrDefault(target, -1);
+    }
+
+    /* Hash search (linked list) */
+    static ListNode hashingSearchLinkedList(Map<Integer, ListNode> map, int target) {
+        // Hash table key: target node value, value: node object
+        // If the key is not in the hash table, return null
+        return map.getOrDefault(target, null);
+    }
+
+    public static void main(String[] args) {
+        int target = 3;
+
+        /* Hash search (array) */
+        int[] nums = { 1, 5, 3, 2, 4, 7, 5, 9, 10, 8 };
+        // Initialize hash table
+        Map<Integer, Integer> map = new HashMap<>();
+        for (int i = 0; i < nums.length; i++) {
+            map.put(nums[i], i); // key: element, value: index
+        }
+        int index = hashingSearchArray(map, target);
+        System.out.println("The index of target element 3 is " + index);
+
+        /* Hash search (linked list) */
+        ListNode head = ListNode.arrToLinkedList(nums);
+        // Initialize hash table
+        Map<Integer, ListNode> map1 = new HashMap<>();
+        while (head != null) {
+            map1.put(head.val, head); // key: node value, value: node
+            head = head.next;
+        }
+        ListNode node = hashingSearchLinkedList(map1, target);
+        System.out.println("The corresponding node object for target node value 3 is " + node);
+    }
+}

en/codes/java/chapter_searching/linear_search.java

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+/**
+ * File: linear_search.java
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+package chapter_searching;
+
+import utils.*;
+
+public class linear_search {
+    /* Linear search (array) */
+    static int linearSearchArray(int[] nums, int target) {
+        // Traverse array
+        for (int i = 0; i < nums.length; i++) {
+            // Found the target element, thus return its index
+            if (nums[i] == target)
+                return i;
+        }
+        // Did not find the target element, thus return -1
+        return -1;
+    }
+
+    /* Linear search (linked list) */
+    static ListNode linearSearchLinkedList(ListNode head, int target) {
+        // Traverse the list
+        while (head != null) {
+            // Found the target node, return it
+            if (head.val == target)
+                return head;
+            head = head.next;
+        }
+        // If the target node is not found, return null
+        return null;
+    }
+
+    public static void main(String[] args) {
+        int target = 3;
+
+        /* Perform linear search in array */
+        int[] nums = { 1, 5, 3, 2, 4, 7, 5, 9, 10, 8 };
+        int index = linearSearchArray(nums, target);
+        System.out.println("The index of target element 3 is " + index);
+
+        /* Perform linear search in linked list */
+        ListNode head = ListNode.arrToLinkedList(nums);
+        ListNode node = linearSearchLinkedList(head, target);
+        System.out.println("The corresponding node object for target node value 3 is " + node);
+    }
+}

en/codes/java/chapter_searching/two_sum.java

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+/**
+ * File: two_sum.java
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+package chapter_searching;
+
+import java.util.*;
+
+public class two_sum {
+    /* Method one: Brute force enumeration */
+    static int[] twoSumBruteForce(int[] nums, int target) {
+        int size = nums.length;
+        // Two-layer loop, time complexity is O(n^2)
+        for (int i = 0; i < size - 1; i++) {
+            for (int j = i + 1; j < size; j++) {
+                if (nums[i] + nums[j] == target)
+                    return new int[] { i, j };
+            }
+        }
+        return new int[0];
+    }
+
+    /* Method two: Auxiliary hash table */
+    static int[] twoSumHashTable(int[] nums, int target) {
+        int size = nums.length;
+        // Auxiliary hash table, space complexity is O(n)
+        Map<Integer, Integer> dic = new HashMap<>();
+        // Single-layer loop, time complexity is O(n)
+        for (int i = 0; i < size; i++) {
+            if (dic.containsKey(target - nums[i])) {
+                return new int[] { dic.get(target - nums[i]), i };
+            }
+            dic.put(nums[i], i);
+        }
+        return new int[0];
+    }
+
+    public static void main(String[] args) {
+        // ======= Test Case =======
+        int[] nums = { 2, 7, 11, 15 };
+        int target = 13;
+
+        // ====== Driver Code ======
+        // Method one
+        int[] res = twoSumBruteForce(nums, target);
+        System.out.println("Method one res = " + Arrays.toString(res));
+        // Method two
+        res = twoSumHashTable(nums, target);
+        System.out.println("Method two res = " + Arrays.toString(res));
+    }
+}