docs: add Japanese translate documents (#1812)

* docs: add Japanese documents (`ja/docs`)

* docs: add Japanese documents (`ja/codes`)

* docs: add Japanese documents

* Remove pythontutor blocks in ja/

* Add an empty at the end of each markdown file.

* Add the missing figures (use the English version temporarily).

* Add index.md for Japanese version.

* Add index.html for Japanese version.

* Add missing index.assets

* Fix backtracking_algorithm.md for Japanese version.

* Add avatar_eltociear.jpg. Fix image links on the Japanese landing page.

* Add the Japanese banner.

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Co-authored-by: krahets <krahets@163.com>

ja/codes/python/chapter_computational_complexity/space_complexity.py

@@ -0,0 +1,90 @@
+"""
+File: space_complexity.py
+Created Time: 2022-11-25
+Author: krahets (krahets@163.com)
+"""
+
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent))
+from modules import ListNode, TreeNode, print_tree
+
+
+def function() -> int:
+    """関数"""
+    # 何らかの操作を実行
+    return 0
+
+
+def constant(n: int):
+    """定数複雑度"""
+    # 定数、変数、オブジェクトは O(1) のスペースを占有
+    a = 0
+    nums = [0] * 10000
+    node = ListNode(0)
+    # ループ内の変数は O(1) のスペースを占有
+    for _ in range(n):
+        c = 0
+    # ループ内の関数は O(1) のスペースを占有
+    for _ in range(n):
+        function()
+
+
+def linear(n: int):
+    """線形複雑度"""
+    # 長さ n のリストは O(n) のスペースを占有
+    nums = [0] * n
+    # 長さ n のハッシュマップは O(n) のスペースを占有
+    hmap = dict[int, str]()
+    for i in range(n):
+        hmap[i] = str(i)
+
+
+def linear_recur(n: int):
+    """線形複雑度（再帰実装）"""
+    print("再帰 n =", n)
+    if n == 1:
+        return
+    linear_recur(n - 1)
+
+
+def quadratic(n: int):
+    """平方複雑度"""
+    # 二次元リストは O(n^2) のスペースを占有
+    num_matrix = [[0] * n for _ in range(n)]
+
+
+def quadratic_recur(n: int) -> int:
+    """平方複雑度（再帰実装）"""
+    if n <= 0:
+        return 0
+    nums = [0] * n
+    print(f"再帰 n = {n} の中で配列の長さ = {len(nums)}")
+    return quadratic_recur(n - 1)
+
+
+def build_tree(n: int) -> TreeNode | None:
+    """指数複雑度（完全二分木の構築）"""
+    if n == 0:
+        return None
+    root = TreeNode(0)
+    root.left = build_tree(n - 1)
+    root.right = build_tree(n - 1)
+    return root
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    n = 5
+    # 定数複雑度
+    constant(n)
+    # 線形複雑度
+    linear(n)
+    linear_recur(n)
+    # 平方複雑度
+    quadratic(n)
+    quadratic_recur(n)
+    # 指数複雑度
+    root = build_tree(n)
+    print_tree(root)