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/python/chapter_divide_and_conquer/binary_search_recur.py

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+"""
+File: binary_search_recur.py
+Created Time: 2023-07-17
+Author: krahets (krahets@163.com)
+"""
+
+
+def dfs(nums: list[int], target: int, i: int, j: int) -> int:
+    """Binary search: problem f(i, j)"""
+    # If the interval is empty, indicating no target element, return -1
+    if i > j:
+        return -1
+    # Calculate midpoint index m
+    m = (i + j) // 2
+    if nums[m] < target:
+        # Recursive subproblem f(m+1, j)
+        return dfs(nums, target, m + 1, j)
+    elif nums[m] > target:
+        # Recursive subproblem f(i, m-1)
+        return dfs(nums, target, i, m - 1)
+    else:
+        # Found the target element, thus return its index
+        return m
+
+
+def binary_search(nums: list[int], target: int) -> int:
+    """Binary search"""
+    n = len(nums)
+    # Solve problem f(0, n-1)
+    return dfs(nums, target, 0, n - 1)
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    target = 6
+    nums = [1, 3, 6, 8, 12, 15, 23, 26, 31, 35]
+
+    # Binary search (double closed interval)
+    index = binary_search(nums, target)
+    print("Index of target element 6 =", index)

en/codes/python/chapter_divide_and_conquer/build_tree.py

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+"""
+File: build_tree.py
+Created Time: 2023-07-15
+Author: krahets (krahets@163.com)
+"""
+
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent))
+from modules import TreeNode, print_tree
+
+
+def dfs(
+    preorder: list[int],
+    inorder_map: dict[int, int],
+    i: int,
+    l: int,
+    r: int,
+) -> TreeNode | None:
+    """Build binary tree: Divide and conquer"""
+    # Terminate when subtree interval is empty
+    if r - l < 0:
+        return None
+    # Initialize root node
+    root = TreeNode(preorder[i])
+    # Query m to divide left and right subtrees
+    m = inorder_map[preorder[i]]
+    # Subproblem: build left subtree
+    root.left = dfs(preorder, inorder_map, i + 1, l, m - 1)
+    # Subproblem: build right subtree
+    root.right = dfs(preorder, inorder_map, i + 1 + m - l, m + 1, r)
+    # Return root node
+    return root
+
+
+def build_tree(preorder: list[int], inorder: list[int]) -> TreeNode | None:
+    """Build binary tree"""
+    # Initialize hash table, storing in-order elements to indices mapping
+    inorder_map = {val: i for i, val in enumerate(inorder)}
+    root = dfs(preorder, inorder_map, 0, 0, len(inorder) - 1)
+    return root
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    preorder = [3, 9, 2, 1, 7]
+    inorder = [9, 3, 1, 2, 7]
+    print(f"Pre-order traversal = {preorder}")
+    print(f"In-order traversal = {inorder}")
+
+    root = build_tree(preorder, inorder)
+    print("The built binary tree is:")
+    print_tree(root)

en/codes/python/chapter_divide_and_conquer/hanota.py

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+"""
+File: hanota.py
+Created Time: 2023-07-16
+Author: krahets (krahets@163.com)
+"""
+
+
+def move(src: list[int], tar: list[int]):
+    """Move a disc"""
+    # Take out a disc from the top of src
+    pan = src.pop()
+    # Place the disc on top of tar
+    tar.append(pan)
+
+
+def dfs(i: int, src: list[int], buf: list[int], tar: list[int]):
+    """Solve the Tower of Hanoi problem f(i)"""
+    # If only one disc remains on src, move it to tar
+    if i == 1:
+        move(src, tar)
+        return
+    # Subproblem f(i-1): move the top i-1 discs from src with the help of tar to buf
+    dfs(i - 1, src, tar, buf)
+    # Subproblem f(1): move the remaining one disc from src to tar
+    move(src, tar)
+    # Subproblem f(i-1): move the top i-1 discs from buf with the help of src to tar
+    dfs(i - 1, buf, src, tar)
+
+
+def solve_hanota(A: list[int], B: list[int], C: list[int]):
+    """Solve the Tower of Hanoi problem"""
+    n = len(A)
+    # Move the top n discs from A with the help of B to C
+    dfs(n, A, B, C)
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    # The tail of the list is the top of the pillar
+    A = [5, 4, 3, 2, 1]
+    B = []
+    C = []
+    print("Initial state:")
+    print(f"A = {A}")
+    print(f"B = {B}")
+    print(f"C = {C}")
+
+    solve_hanota(A, B, C)
+
+    print("After the discs are moved:")
+    print(f"A = {A}")
+    print(f"B = {B}")
+    print(f"C = {C}")