This commit is contained in:
krahets
2024-04-11 01:11:20 +08:00
parent a6adc8e20a
commit 739f8a31bb
85 changed files with 1555 additions and 979 deletions

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@ -1180,7 +1180,7 @@ The following code implements a binary tree based on array representation, inclu
}
/* 获取索引为 i 节点的值 */
fun value(i: Int): Int? {
fun _val(i: Int): Int? {
// 若索引越界,则返回 null ,代表空位
if (i < 0 || i >= size()) return null
return tree[i]
@ -1206,8 +1206,8 @@ The following code implements a binary tree based on array representation, inclu
val res = mutableListOf<Int?>()
// 直接遍历数组
for (i in 0..<size()) {
if (value(i) != null)
res.add(value(i))
if (_val(i) != null)
res.add(_val(i))
}
return res
}
@ -1215,19 +1215,19 @@ The following code implements a binary tree based on array representation, inclu
/* 深度优先遍历 */
fun dfs(i: Int, order: String, res: MutableList<Int?>) {
// 若为空位,则返回
if (value(i) == null)
if (_val(i) == null)
return
// 前序遍历
if ("pre" == order)
res.add(value(i))
res.add(_val(i))
dfs(left(i), order, res)
// 中序遍历
if ("in" == order)
res.add(value(i))
res.add(_val(i))
dfs(right(i), order, res)
// 后序遍历
if ("post" == order)
res.add(value(i))
res.add(_val(i))
}
/* 前序遍历 */

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@ -2012,20 +2012,20 @@ The node insertion operation in AVL trees is similar to that in binary search tr
```kotlin title="avl_tree.kt"
/* 插入节点 */
fun insert(value: Int) {
root = insertHelper(root, value)
fun insert(_val: Int) {
root = insertHelper(root, _val)
}
/* 递归插入节点(辅助方法) */
fun insertHelper(n: TreeNode?, value: Int): TreeNode {
fun insertHelper(n: TreeNode?, _val: Int): TreeNode {
if (n == null)
return TreeNode(value)
return TreeNode(_val)
var node = n
/* 1. 查找插入位置并插入节点 */
if (value < node.value)
node.left = insertHelper(node.left, value)
else if (value > node.value)
node.right = insertHelper(node.right, value)
if (_val < node._val)
node.left = insertHelper(node.left, _val)
else if (_val > node._val)
node.right = insertHelper(node.right, _val)
else
return node // 重复节点不插入,直接返回
updateHeight(node) // 更新节点高度
@ -2595,18 +2595,18 @@ Similarly, based on the method of removing nodes in binary search trees, rotatio
```kotlin title="avl_tree.kt"
/* 删除节点 */
fun remove(value: Int) {
root = removeHelper(root, value)
fun remove(_val: Int) {
root = removeHelper(root, _val)
}
/* 递归删除节点(辅助方法) */
fun removeHelper(n: TreeNode?, value: Int): TreeNode? {
fun removeHelper(n: TreeNode?, _val: Int): TreeNode? {
var node = n ?: return null
/* 1. 查找节点并删除 */
if (value < node.value)
node.left = removeHelper(node.left, value)
else if (value > node.value)
node.right = removeHelper(node.right, value)
if (_val < node._val)
node.left = removeHelper(node.left, _val)
else if (_val > node._val)
node.right = removeHelper(node.right, _val)
else {
if (node.left == null || node.right == null) {
val child = if (node.left != null)
@ -2625,8 +2625,8 @@ Similarly, based on the method of removing nodes in binary search trees, rotatio
while (temp!!.left != null) {
temp = temp.left
}
node.right = removeHelper(node.right, temp.value)
node.value = temp.value
node.right = removeHelper(node.right, temp._val)
node._val = temp._val
}
}
updateHeight(node) // 更新节点高度

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@ -299,10 +299,10 @@ The search operation in a binary search tree works on the same principle as the
// 循环查找,越过叶节点后跳出
while (cur != null) {
// 目标节点在 cur 的右子树中
cur = if (cur.value < num)
cur = if (cur._val < num)
cur.right
// 目标节点在 cur 的左子树中
else if (cur.value > num)
else if (cur._val > num)
cur.left
// 找到目标节点,跳出循环
else
@ -751,11 +751,11 @@ In the code implementation, note the following two points.
// 循环查找,越过叶节点后跳出
while (cur != null) {
// 找到重复节点,直接返回
if (cur.value == num)
if (cur._val == num)
return
pre = cur
// 插入位置在 cur 的右子树中
cur = if (cur.value < num)
cur = if (cur._val < num)
cur.right
// 插入位置在 cur 的左子树中
else
@ -763,7 +763,7 @@ In the code implementation, note the following two points.
}
// 插入节点
val node = TreeNode(num)
if (pre?.value!! < num)
if (pre?._val!! < num)
pre.right = node
else
pre.left = node
@ -1497,11 +1497,11 @@ The operation of removing a node also uses $O(\log n)$ time, where finding the n
// 循环查找,越过叶节点后跳出
while (cur != null) {
// 找到待删除节点,跳出循环
if (cur.value == num)
if (cur._val == num)
break
pre = cur
// 待删除节点在 cur 的右子树中
cur = if (cur.value < num)
cur = if (cur._val < num)
cur.right
// 待删除节点在 cur 的左子树中
else
@ -1535,9 +1535,9 @@ The operation of removing a node also uses $O(\log n)$ time, where finding the n
tmp = tmp.left
}
// 递归删除节点 tmp
remove(tmp.value)
remove(tmp._val)
// 用 tmp 覆盖 cur
cur.value = tmp.value
cur._val = tmp._val
}
}
```

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@ -305,7 +305,7 @@ Breadth-first traversal is usually implemented with the help of a "queue". The q
val list = mutableListOf<Int>()
while (queue.isNotEmpty()) {
val node = queue.poll() // 队列出队
list.add(node?.value!!) // 保存节点值
list.add(node?._val!!) // 保存节点值
if (node.left != null)
queue.offer(node.left) // 左子节点入队
if (node.right != null)
@ -764,7 +764,7 @@ Depth-first search is usually implemented based on recursion:
fun preOrder(root: TreeNode?) {
if (root == null) return
// 访问优先级:根节点 -> 左子树 -> 右子树
list.add(root.value)
list.add(root._val)
preOrder(root.left)
preOrder(root.right)
}
@ -774,7 +774,7 @@ Depth-first search is usually implemented based on recursion:
if (root == null) return
// 访问优先级:左子树 -> 根节点 -> 右子树
inOrder(root.left)
list.add(root.value)
list.add(root._val)
inOrder(root.right)
}
@ -784,7 +784,7 @@ Depth-first search is usually implemented based on recursion:
// 访问优先级:左子树 -> 右子树 -> 根节点
postOrder(root.left)
postOrder(root.right)
list.add(root.value)
list.add(root._val)
}
```