add zig codes for Section 'Hash Map' and 'Linear Search'

codes/zig/chapter_searching/linear_search.zig

@@ -0,0 +1,55 @@
+// File: linear_search.zig
+// Created Time: 2023-01-13
+// Author: sjinzh (sjinzh@gmail.com)
+
+const std = @import("std");
+const inc = @import("include");
+
+// 线性查找（数组）
+fn linearSearchList(comptime T: type, nums: std.ArrayList(T), target: T) T {
+    // 遍历数组
+    for (nums.items) |num, i| {
+        // 找到目标元素， 返回其索引
+        if (num == target) {
+            return @intCast(T, i);
+        }
+    }
+    // 未找到目标元素，返回 -1
+    return -1;
+}
+
+// 线性查找（链表）
+pub fn linearSearchLinkedList(comptime T: type, node: ?*inc.ListNode(T), target: T) ?*inc.ListNode(T) {
+    var head = node;
+    // 遍历链表
+    while (head != null) {
+        // 找到目标结点，返回之
+        if (head.?.val == target) return head;
+        head = head.?.next;
+    }
+    return null;
+}
+
+// Driver Code
+pub fn main() !void {
+    var target: i32 = 3;
+
+    // 在数组中执行线性查找
+    var nums = std.ArrayList(i32).init(std.heap.page_allocator);
+    defer nums.deinit();
+    try nums.appendSlice(&[_]i32{ 1, 5, 3, 2, 4, 7, 5, 9, 10, 8 });
+    var index = linearSearchList(i32, nums, target);
+    std.debug.print("目标元素 3 的索引 = {}\n", .{index});
+
+    // 在链表中执行线性查找
+    var mem_arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
+    defer mem_arena.deinit();
+    const mem_allocator = mem_arena.allocator();
+    var head = try inc.ListUtil.listToLinkedList(i32, mem_allocator, nums);
+    var node = linearSearchLinkedList(i32, head, target);
+    std.debug.print("目标结点值 3 的对应结点对象为 {any}", .{node});
+
+    const getchar = try std.io.getStdIn().reader().readByte();
+    _ = getchar;
+}
+