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const std = @import("std");
const Allocator = std.mem.Allocator;
const testing = std.testing;
pub fn Node(comptime T: type) type {
return struct {
const Self = @This();
left: ?*Self = null,
right: ?*Self = null,
value: T,
pub fn init(allocator: *Allocator, value: T) !*Self {
const self = try allocator.create(Self);
self.* = .{ .value = value, .left = null, .right = null };
return self;
}
pub fn deinit(self: *Self, allocator: *Allocator) void {
if (self.left) |left| left.deinit(allocator);
if (self.right) |right| right.deinit(allocator);
allocator.destroy(self);
}
};
}
pub fn BST(comptime T: type) type {
return struct {
const Self = @This();
const NodeT = Node(T);
root: ?*NodeT = null,
allocator: *Allocator,
pub fn init(allocator: *Allocator) Self {
return Self{ .allocator = allocator };
}
pub fn deinit(self: *Self) void {
if (self.root) |root| root.deinit(self.allocator);
}
pub fn insert(self: *Self, value: T) !void {
if (self.root == null) {
self.root = try NodeT.init(self.allocator, value);
} else {
try self.insertRecursive(self.root.?, value);
}
}
fn insertRecursive(self: *Self, node: *NodeT, value: T) !void {
if (value < node.value) {
if (node.left == null) {
node.left = try NodeT.init(self.allocator, value);
} else {
try self.insertRecursive(node.left.?, value);
}
} else if (value > node.value) {
if (node.right == null) {
node.right = try NodeT.init(self.allocator, value);
} else {
try self.insertRecursive(node.right.?, value);
}
}
}
pub fn search(self: *Self, value: T) bool {
return self.searchRecursive(self.root, value);
}
fn searchRecursive(self: *Self, node: ?*NodeT, value: T) bool {
if (node) |n| {
if (value == n.value) return true;
if (value < n.value) return self.searchRecursive(n.left, value);
if (value > n.value) return self.searchRecursive(n.right, value);
}
return false;
}
pub fn inorderTraversal(self: *Self, list: *std.ArrayList(T)) !void {
try self.inorderTraversalRecursive(self.root, list);
}
fn inorderTraversalRecursive(self: *Self, node: ?*NodeT, list: *std.ArrayList(T)) !void {
if (node) |n| {
try self.inorderTraversalRecursive(n.left, list);
try list.append(n.value);
try self.inorderTraversalRecursive(n.right, list);
}
}
pub fn min(self: *Self) ?T {
var current = self.root;
while (current) |n| {
if (n.left == null) return n.value;
current = n.left;
}
return null;
}
pub fn max(self: *Self) ?T {
var current = self.root;
while (current) |n| {
if (n.right == null) return n.value;
current = n.right;
}
return null;
}
};
}
test "BST operations" {
var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
defer arena.deinit();
var allocator = arena.allocator();
var bst = BST(i32).init(&allocator);
defer bst.deinit();
// Test insert and search
try bst.insert(5);
try bst.insert(3);
try bst.insert(7);
try bst.insert(1);
try bst.insert(9);
try testing.expect(bst.search(5));
try testing.expect(bst.search(1));
try testing.expect(bst.search(9));
try testing.expect(!bst.search(4));
try testing.expect(!bst.search(10));
// Test min and max
try testing.expectEqual(@as(?i32, 1), bst.min());
try testing.expectEqual(@as(?i32, 9), bst.max());
// Test inorder traversal
var list = std.ArrayList(i32).init(allocator);
defer list.deinit();
try bst.inorderTraversal(&list);
const expected = [_]i32{ 1, 3, 5, 7, 9 };
try testing.expectEqualSlices(i32, &expected, list.items);
}
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