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_computational_complexity/recursion.py

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+"""
+File: recursion.py
+Created Time: 2023-08-24
+Author: krahets (krahets@163.com)
+"""
+
+
+def recur(n: int) -> int:
+    """Recursion"""
+    # Termination condition
+    if n == 1:
+        return 1
+    # Recursive: recursive call
+    res = recur(n - 1)
+    # Return: return result
+    return n + res
+
+
+def for_loop_recur(n: int) -> int:
+    """Simulate recursion with iteration"""
+    # Use an explicit stack to simulate the system call stack
+    stack = []
+    res = 0
+    # Recursive: recursive call
+    for i in range(n, 0, -1):
+        # Simulate "recursive" by "pushing onto the stack"
+        stack.append(i)
+    # Return: return result
+    while stack:
+        # Simulate "return" by "popping from the stack"
+        res += stack.pop()
+    # res = 1+2+3+...+n
+    return res
+
+
+def tail_recur(n, res):
+    """Tail recursion"""
+    # Termination condition
+    if n == 0:
+        return res
+    # Tail recursive call
+    return tail_recur(n - 1, res + n)
+
+
+def fib(n: int) -> int:
+    """Fibonacci sequence: Recursion"""
+    # Termination condition f(1) = 0, f(2) = 1
+    if n == 1 or n == 2:
+        return n - 1
+    # Recursive call f(n) = f(n-1) + f(n-2)
+    res = fib(n - 1) + fib(n - 2)
+    # Return result f(n)
+    return res
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    n = 5
+    res = recur(n)
+    print(f"\nRecursive function sum result res = {res}")
+
+    res = for_loop_recur(n)
+    print(f"\nSimulate recursion with iteration sum result res = {res}")
+
+    res = tail_recur(n, 0)
+    print(f"\nTail recursive function sum result res = {res}")
+
+    res = fib(n)
+    print(f"\nThe n th term of the Fibonacci sequence is {res}")