Refine some details and coding style for Rust codes (#344)

* Refine some details and coding style for Rust codes

* Update coding style for Rust codes

* Update time_complexity.rs

* Update array.rs

* Update leetcode_two_sum.rs

* Update hash_map.rs

* Update file headers

* Update coding style for Rust codes and Zig codes

* Update coding style for Rust codes and Zig codes

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

codes/zig/chapter_stack_and_queue/stack.zig

@@ -36,8 +36,8 @@ pub fn main() !void {
     std.debug.print("\n栈的长度 size = {}", .{size});
 
     // 判断栈是否为空
-    var empty = if (stack.items.len == 0) true else false;
-    std.debug.print("\n栈是否为空 = {}", .{empty});
+    var is_empty = if (stack.items.len == 0) true else false;
+    std.debug.print("\n栈是否为空 = {}", .{is_empty});
 
     _ = try std.io.getStdIn().reader().readByte();
 }