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fix build_tree, binary_search_tree.cs

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fix two figures
This commit is contained in:
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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codes/go/chapter_divide_and_conquer/build_tree.go
+7 -7
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@@ -7,7 +7,7 @@ package chapter_divide_and_conquer
import . "github.com/krahets/hello-algo/pkg"
/* 构建二叉树：分治 */
func dfsBuildTree(preorder, inorder []int, hmap map[int]int, i, l, r int) *TreeNode {
func dfsBuildTree(preorder []int, inorderMap map[int]int, i, l, r int) *TreeNode {
// 子树区间为空时终止
if r-l < 0 {
return nil
@@ -15,11 +15,11 @@ func dfsBuildTree(preorder, inorder []int, hmap map[int]int, i, l, r int) *TreeN
// 初始化根节点
root := NewTreeNode(preorder[i])
// 查询 m ，从而划分左右子树
m := hmap[preorder[i]]
m := inorderMap[preorder[i]]
// 子问题：构建左子树
root.Left = dfsBuildTree(preorder, inorder, hmap, i+1, l, m-1)
root.Left = dfsBuildTree(preorder, inorderMap, i+1, l, m-1)
// 子问题：构建右子树
root.Right = dfsBuildTree(preorder, inorder, hmap, i+1+m-l, m+1, r)
root.Right = dfsBuildTree(preorder, inorderMap, i+1+m-l, m+1, r)
// 返回根节点
return root
}
@@ -27,11 +27,11 @@ func dfsBuildTree(preorder, inorder []int, hmap map[int]int, i, l, r int) *TreeN
/* 构建二叉树 */
func buildTree(preorder, inorder []int) *TreeNode {
// 初始化哈希表，存储 inorder 元素到索引的映射
hmap := make(map[int]int, len(inorder))
inorderMap := make(map[int]int, len(inorder))
for i := 0; i < len(inorder); i++ {
hmap[inorder[i]] = i
inorderMap[inorder[i]] = i
}
root := dfsBuildTree(preorder, inorder, hmap, 0, 0, len(inorder)-1)
root := dfsBuildTree(preorder, inorderMap, 0, 0, len(inorder)-1)
return root
}