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fix build_tree, binary_search_tree.cs

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fix two figures
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krahets
2023-09-15 02:08:09 +08:00
parent af2aeb0897
commit cb9c14f5ff
13 changed files with 69 additions and 72 deletions
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14
codes/rust/chapter_divide_and_conquer/build_tree.rs
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@@ -10,17 +10,17 @@ include!("../include/include.rs");
use tree_node::TreeNode;
/* 构建二叉树：分治 */
fn dfs(preorder: &[i32], inorder: &[i32], hmap: &HashMap<i32, i32>, i: i32, l: i32, r: i32) -> Option<Rc<RefCell<TreeNode>>> {
fn dfs(preorder: &[i32], inorderMap: &HashMap<i32, i32>, i: i32, l: i32, r: i32) -> Option<Rc<RefCell<TreeNode>>> {
// 子树区间为空时终止
if r - l < 0 { return None; }
// 初始化根节点
let root = TreeNode::new(preorder[i as usize]);
// 查询 m ，从而划分左右子树
let m = hmap.get(&preorder[i as usize]).unwrap();
let m = inorderMap.get(&preorder[i as usize]).unwrap();
// 子问题：构建左子树
root.borrow_mut().left = dfs(preorder, inorder, hmap, i + 1, l, m - 1);
root.borrow_mut().left = dfs(preorder, inorderMap, i + 1, l, m - 1);
// 子问题：构建右子树
root.borrow_mut().right = dfs(preorder, inorder, hmap, i + 1 + m - l, m + 1, r);
root.borrow_mut().right = dfs(preorder, inorderMap, i + 1 + m - l, m + 1, r);
// 返回根节点
Some(root)
}
@@ -28,11 +28,11 @@ fn dfs(preorder: &[i32], inorder: &[i32], hmap: &HashMap<i32, i32>, i: i32, l: i
/* 构建二叉树 */
fn build_tree(preorder: &[i32], inorder: &[i32]) -> Option<Rc<RefCell<TreeNode>>> {
// 初始化哈希表，存储 inorder 元素到索引的映射
let mut hmap: HashMap<i32, i32> = HashMap::new();
let mut inorderMap: HashMap<i32, i32> = HashMap::new();
for i in 0..inorder.len() {
hmap.insert(inorder[i], i as i32);
inorderMap.insert(inorder[i], i as i32);
}
let root = dfs(preorder, inorder, &hmap, 0, 0, inorder.len() as i32 - 1);
let root = dfs(preorder, &inorderMap, 0, 0, inorder.len() as i32 - 1);
root
}