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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codes/rust/Cargo.toml

@@ -4,6 +4,16 @@ version = "0.1.0"
 edition = "2021"
 publish = false
 
+# Run Command: cargo run --bin complexity_exercises
+[[bin]]
+name = "complexity_exercises"
+path = "chapter_computational_complexity/complexity_exercises.rs"
+
+# Run Command: cargo run --bin fast_power
+[[bin]]
+name = "fast_power"
+path = "chapter_divide_and_conquer/fast_power.rs"
+
 # Run Command: cargo run --bin time_complexity
 [[bin]]
 name = "time_complexity"

codes/rust/chapter_computational_complexity/complexity_exercises.rs

@@ -0,0 +1,61 @@
+/*
+ * File: complexity_exercises.rs
+ * Created Time: 2026-08-18
+ * Author: Hello Algo Team
+ */
+
+/* 迭代求和 */
+fn sum_iter(n: i32) -> i32 {
+    let mut res = 0;
+    for i in 1..=n {
+        res += i;
+    }
+    res
+}
+
+/* 递归求和 */
+fn sum_recur(n: i32) -> i32 {
+    if n == 1 {
+        return 1;
+    }
+    n + sum_recur(n - 1)
+}
+
+/* 线性阶循环 */
+fn linear_loop(n: i32) -> i32 {
+    let mut res = 0;
+    for i in 0..n {
+        res += i;
+    }
+    res
+}
+
+/* 平方阶循环 */
+fn quadratic_loop(n: i32) -> i32 {
+    let mut res = 0;
+    for i in 0..n {
+        for j in i..n {
+            res += j;
+        }
+    }
+    res
+}
+
+/* 对数阶循环 */
+fn logarithmic_loop(mut n: i32) -> i32 {
+    while n > 1 {
+        n /= 2;
+    }
+    n
+}
+
+fn main() {
+    assert_eq!(sum_iter(1), 1);
+    assert_eq!(sum_recur(1), 1);
+    assert_eq!(sum_iter(4), 10);
+    assert_eq!(sum_recur(4), 10);
+    assert_eq!(linear_loop(4), 6);
+    assert_eq!(quadratic_loop(4), 20);
+    assert_eq!(logarithmic_loop(4), 1);
+    assert_eq!(logarithmic_loop(5), 1);
+}

codes/rust/chapter_divide_and_conquer/fast_power.rs

@@ -0,0 +1,23 @@
+/*
+ * File: fast_power.rs
+ * Created Time: 2026-08-18
+ * Author: Hello Algo Team
+ */
+
+/* 快速幂 */
+fn fast_pow(x: i32, n: i32) -> i32 {
+    if n == 0 {
+        return 1;
+    }
+    let half = fast_pow(x, n / 2);
+    if n % 2 == 0 {
+        return half * half;
+    }
+    half * half * x
+}
+
+fn main() {
+    assert_eq!(fast_pow(7, 0), 1);
+    assert_eq!(fast_pow(3, 5), 243);
+    assert_eq!(fast_pow(2, 6), 64);
+}