zig : upgrade codes && rust : add codes for chapter_searching and chapter_dynamic_programming. (#591)

* zig : update zig codes

* rust : add codes for linear_search and hashing_search

* rust : add codes for linear_search and hashing_search

* rust : add codes for chapter_dynamic_programming

codes/zig/chapter_computational_complexity/time_complexity.zig

@@ -54,7 +54,7 @@ fn quadratic(n: i32) i32 {
 fn bubbleSort(nums: []i32) i32 {
     var count: i32 = 0;  // 计数器 
     // 外循环：未排序区间为 [0, i]
-    var i: i32 = @intCast(i32, nums.len ) - 1;
+    var i: i32 = @as(i32, @intCast(nums.len)) - 1;
     while (i > 0) : (i -= 1) {
         var j: usize = 0;
         // 内循环：将未排序区间 [0, i] 中的最大元素交换至该区间的最右端 
@@ -154,7 +154,7 @@ pub fn main() !void {
     count = quadratic(n);
     std.debug.print("平方阶的计算操作数量 = {}\n", .{count});
     for (&nums, 0..) |*num, i| {
-        num.* = n - @intCast(i32, i);  // [n,n-1,...,2,1]
+        num.* = n - @as(i32, @intCast(i));  // [n,n-1,...,2,1]
     }
     count = bubbleSort(&nums);
     std.debug.print("平方阶（冒泡排序）的计算操作数量 = {}\n", .{count});