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/time_complexity.py

@@ -0,0 +1,151 @@
+"""
+File: time_complexity.py
+Created Time: 2022-11-25
+Author: krahets (krahets@163.com)
+"""
+
+
+def constant(n: int) -> int:
+    """定数複雑度"""
+    count = 0
+    size = 100000
+    for _ in range(size):
+        count += 1
+    return count
+
+
+def linear(n: int) -> int:
+    """線形複雑度"""
+    count = 0
+    for _ in range(n):
+        count += 1
+    return count
+
+
+def array_traversal(nums: list[int]) -> int:
+    """線形複雑度（配列の走査）"""
+    count = 0
+    # ループ回数は配列の長さに比例する
+    for num in nums:
+        count += 1
+    return count
+
+
+def quadratic(n: int) -> int:
+    """二次複雑度"""
+    count = 0
+    # ループ回数はデータサイズnの二乗に比例する
+    for i in range(n):
+        for j in range(n):
+            count += 1
+    return count
+
+
+def bubble_sort(nums: list[int]) -> int:
+    """二次複雑度（バブルソート）"""
+    count = 0  # カウンタ
+    # 外側のループ: 未ソート範囲は [0, i]
+    for i in range(len(nums) - 1, 0, -1):
+        # 内側のループ: 未ソート範囲 [0, i] の最大要素を右端にスワップ
+        for j in range(i):
+            if nums[j] > nums[j + 1]:
+                # nums[j] と nums[j + 1] をスワップ
+                tmp: int = nums[j]
+                nums[j] = nums[j + 1]
+                nums[j + 1] = tmp
+                count += 3  # 要素のスワップは3つの個別操作を含む
+    return count
+
+
+def exponential(n: int) -> int:
+    """指数複雑度（ループ実装）"""
+    count = 0
+    base = 1
+    # セルは毎回2つに分裂し、1, 2, 4, 8, ..., 2^(n-1) の数列を形成する
+    for _ in range(n):
+        for _ in range(base):
+            count += 1
+        base *= 2
+    # count = 1 + 2 + 4 + 8 + .. + 2^(n-1) = 2^n - 1
+    return count
+
+
+def exp_recur(n: int) -> int:
+    """指数複雑度（再帰実装）"""
+    if n == 1:
+        return 1
+    return exp_recur(n - 1) + exp_recur(n - 1) + 1
+
+
+def logarithmic(n: int) -> int:
+    """対数複雑度（ループ実装）"""
+    count = 0
+    while n > 1:
+        n = n / 2
+        count += 1
+    return count
+
+
+def log_recur(n: int) -> int:
+    """対数複雑度（再帰実装）"""
+    if n <= 1:
+        return 0
+    return log_recur(n / 2) + 1
+
+
+def linear_log_recur(n: int) -> int:
+    """線形対数複雑度"""
+    if n <= 1:
+        return 1
+    count: int = linear_log_recur(n // 2) + linear_log_recur(n // 2)
+    for _ in range(n):
+        count += 1
+    return count
+
+
+def factorial_recur(n: int) -> int:
+    """階乗複雑度（再帰実装）"""
+    if n == 0:
+        return 1
+    count = 0
+    # 1つからnに分岐
+    for _ in range(n):
+        count += factorial_recur(n - 1)
+    return count
+
+
+"""ドライバコード"""
+if __name__ == "__main__":
+    # nを変更して、様々な複雑度での操作回数の変化傾向を体験できる
+    n = 8
+    print("入力データサイズ n =", n)
+
+    count: int = constant(n)
+    print("定数複雑度の操作回数 =", count)
+
+    count: int = linear(n)
+    print("線形複雑度の操作回数 =", count)
+    count: int = array_traversal([0] * n)
+    print("線形複雑度（配列の走査）の操作回数 =", count)
+
+    count: int = quadratic(n)
+    print("二次複雑度の操作回数 =", count)
+    nums = [i for i in range(n, 0, -1)]  # [n, n-1, ..., 2, 1]
+    count: int = bubble_sort(nums)
+    print("二次複雑度（バブルソート）の操作回数 =", count)
+
+    count: int = exponential(n)
+    print("指数複雑度（ループ実装）の操作回数 =", count)
+    count: int = exp_recur(n)
+    print("指数複雑度（再帰実装）の操作回数 =", count)
+
+    count: int = logarithmic(n)
+    print("対数複雑度（ループ実装）の操作回数 =", count)
+    count: int = log_recur(n)
+    print("対数複雑度（再帰実装）の操作回数 =", count)
+
+    count: int = linear_log_recur(n)
+    print("線形対数複雑度（再帰実装）の操作回数 =", count)
+
+    count: int = factorial_recur(n)
+    print("階乗複雑度（再帰実装）の操作回数 =", count)