You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
57 lines
2.0 KiB
57 lines
2.0 KiB
// File: binary_tree_bfs.zig
|
|
// Created Time: 2023-01-15
|
|
// Author: codingonion (coderonion@gmail.com)
|
|
|
|
const std = @import("std");
|
|
const inc = @import("include");
|
|
|
|
// 层序遍历
|
|
fn levelOrder(comptime T: type, mem_allocator: std.mem.Allocator, root: *inc.TreeNode(T)) !std.ArrayList(T) {
|
|
// 初始化队列，加入根节点
|
|
const L = std.TailQueue(*inc.TreeNode(T));
|
|
var queue = L{};
|
|
var root_node = try mem_allocator.create(L.Node);
|
|
root_node.data = root;
|
|
queue.append(root_node);
|
|
// 初始化一个列表，用于保存遍历序列
|
|
var list = std.ArrayList(T).init(std.heap.page_allocator);
|
|
while (queue.len > 0) {
|
|
var queue_node = queue.popFirst().?; // 队列出队
|
|
var node = queue_node.data;
|
|
try list.append(node.val); // 保存节点值
|
|
if (node.left != null) {
|
|
var tmp_node = try mem_allocator.create(L.Node);
|
|
tmp_node.data = node.left.?;
|
|
queue.append(tmp_node); // 左子节点入队
|
|
}
|
|
if (node.right != null) {
|
|
var tmp_node = try mem_allocator.create(L.Node);
|
|
tmp_node.data = node.right.?;
|
|
queue.append(tmp_node); // 右子节点入队
|
|
}
|
|
}
|
|
return list;
|
|
}
|
|
|
|
// Driver Code
|
|
pub fn main() !void {
|
|
// 初始化内存分配器
|
|
var mem_arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
|
|
defer mem_arena.deinit();
|
|
const mem_allocator = mem_arena.allocator();
|
|
|
|
// 初始化二叉树
|
|
// 这里借助了一个从数组直接生成二叉树的函数
|
|
var nums = [_]i32{1, 2, 3, 4, 5, 6, 7};
|
|
var root = try inc.TreeUtil.arrToTree(i32, mem_allocator, &nums);
|
|
std.debug.print("初始化二叉树\n", .{});
|
|
try inc.PrintUtil.printTree(root, null, false);
|
|
|
|
// 层序遍历
|
|
var list = try levelOrder(i32, mem_allocator, root.?);
|
|
defer list.deinit();
|
|
std.debug.print("\n层序遍历的节点打印序列 = ", .{});
|
|
inc.PrintUtil.printList(i32, list);
|
|
|
|
_ = try std.io.getStdIn().reader().readByte();
|
|
} |