Add multilingual exercise code (#1959)

Replace the exercise pages' Python-only snippets with source-backed implementations for the 13 visible programming languages, and localize reader-facing comments by site language. Zig remains out of scope.

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ru/codes/python/chapter_divide_and_conquer/fast_power.py

@@ -0,0 +1,21 @@
+"""
+File: fast_power.py
+Created Time: 2026-08-18
+Author: Hello Algo Team
+"""
+
+
+def fast_pow(x: int, n: int) -> int:
+    """Быстрое возведение в степень"""
+    if n == 0:
+        return 1
+    half = fast_pow(x, n // 2)
+    if n % 2 == 0:
+        return half * half
+    return half * half * x
+
+
+if __name__ == "__main__":
+    assert fast_pow(7, 0) == 1
+    assert fast_pow(3, 5) == 243
+    assert fast_pow(2, 6) == 64