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krahets
2024-04-13 21:17:44 +08:00
parent 9332a91e26
commit 6afa70e7bc
55 changed files with 334 additions and 182 deletions
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docs/chapter_array_and_linkedlist/linked_list.md
+1
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@@ -813,6 +813,7 @@ comments: true
fun remove(n0: ListNode?) {
if (n0?.next == null)
return
// n0 -> P -> n1
val p = n0.next
val n1 = p?.next
n0.next = n1
docs/chapter_array_and_linkedlist/list.md
+6 -6
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@@ -385,10 +385,10 @@ comments: true
nums.Add(4);
/* 在中间插入元素 */
nums.Insert(3, 6);
nums.Insert(3, 6); // 在索引 3 处插入数字 6
/* 删除元素 */
nums.RemoveAt(3);
nums.RemoveAt(3); // 删除索引 3 处的元素
```
=== "Go"
@@ -445,10 +445,10 @@ comments: true
nums.push(4);
/* 在中间插入元素 */
nums.splice(3, 0, 6);
nums.splice(3, 0, 6); // 在索引 3 处插入数字 6
/* 删除元素 */
nums.splice(3, 1);
nums.splice(3, 1); // 删除索引 3 处的元素
```
=== "TS"
@@ -465,10 +465,10 @@ comments: true
nums.push(4);
/* 在中间插入元素 */
nums.splice(3, 0, 6);
nums.splice(3, 0, 6); // 在索引 3 处插入数字 6
/* 删除元素 */
nums.splice(3, 1);
nums.splice(3, 1); // 删除索引 3 处的元素
```
=== "Dart"
docs/chapter_computational_complexity/iteration_and_recursion.md
+1
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@@ -1992,6 +1992,7 @@ comments: true
var res = 0
// 递: 递归调用
for (i in n downTo 0) {
// 通过“入栈操作”模拟“递”
stack.push(i)
}
// 归: 返回结果
docs/chapter_computational_complexity/time_complexity.md
+6 -6
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@@ -1431,7 +1431,6 @@ $$
/* 线性阶 */
fun linear(n: Int): Int {
var count = 0
// 循环次数与数组长度成正比
for (i in 0..<n)
count++
return count
@@ -2175,7 +2174,9 @@ $$
for (j in 0..<i) {
if (nums[j] > nums[j + 1]) {
// 交换 nums[j] 与 nums[j + 1]
nums[j] = nums[j + 1].also { nums[j + 1] = nums[j] }
val temp = nums[j]
nums[j] = nums[j + 1]
nums[j + 1] = temp
count += 3 // 元素交换包含 3 个单元操作
}
}
@@ -2452,8 +2453,8 @@ $$
/* 指数阶（循环实现） */
fun exponential(n: Int): Int {
var count = 0
// 细胞每轮一分为二，形成数列 1, 2, 4, 8, ..., 2^(n-1)
var base = 1
// 细胞每轮一分为二，形成数列 1, 2, 4, 8, ..., 2^(n-1)
for (i in 0..<n) {
for (j in 0..<base) {
count++
@@ -3859,12 +3860,11 @@ $$
for (i in 0..<n) {
nums[i] = i + 1
}
val mutableList = nums.toMutableList()
// 随机打乱数组元素
mutableList.shuffle()
nums.shuffle()
val res = arrayOfNulls<Int>(n)
for (i in 0..<n) {
res[i] = mutableList[i]
res[i] = nums[i]
}
return res
}
docs/chapter_dynamic_programming/intro_to_dynamic_programming.md
+5 -1
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@@ -184,7 +184,9 @@ comments: true
if state + choice > n {
continue
}
// 尝试：做出选择，更新状态
backtrack(choices: choices, state: state + choice, n: n, res: &res)
// 回退
}
}
@@ -1597,7 +1599,9 @@ $$
var a = 1
var b = 2
for (i in 3..n) {
b += a.also { a = b }
val temp = b
b += a
a = temp
}
return b
}
docs/chapter_dynamic_programming/knapsack_problem.md
+3 -12
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@@ -1036,11 +1036,7 @@ $$
```kotlin title="knapsack.kt"
/* 0-1 背包：动态规划 */
fun knapsackDP(
wgt: IntArray,
_val: IntArray,
cap: Int
): Int {
fun knapsackDP(wgt: IntArray, _val: IntArray, cap: Int): Int {
val n = wgt.size
// 初始化 dp 表
val dp = Array(n + 1) { IntArray(cap + 1) }
@@ -1429,11 +1425,7 @@ $$
```kotlin title="knapsack.kt"
/* 0-1 背包：空间优化后的动态规划 */
fun knapsackDPComp(
wgt: IntArray,
_val: IntArray,
cap: Int
): Int {
fun knapsackDPComp(wgt: IntArray, _val: IntArray, cap: Int): Int {
val n = wgt.size
// 初始化 dp 表
val dp = IntArray(cap + 1)
@@ -1443,8 +1435,7 @@ $$
for (c in cap downTo 1) {
if (wgt[i - 1] <= c) {
// 不选和选物品 i 这两种方案的较大值
dp[c] =
max(dp[c], dp[c - wgt[i - 1]] + _val[i - 1])
dp[c] = max(dp[c], dp[c - wgt[i - 1]] + _val[i - 1])
}
}
}
docs/chapter_graph/graph_operations.md
+13 -13
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@@ -1103,8 +1103,8 @@ comments: true
if (i < 0 || j < 0 || i >= size() || j >= size() || i == j)
throw IndexOutOfBoundsException()
// 在无向图中，邻接矩阵关于主对角线对称，即满足 (i, j) == (j, i)
adjMat[i][j] = 1;
adjMat[j][i] = 1;
adjMat[i][j] = 1
adjMat[j][i] = 1
}
/* 删除边 */
@@ -1113,15 +1113,15 @@ comments: true
// 索引越界与相等处理
if (i < 0 || j < 0 || i >= size() || j >= size() || i == j)
throw IndexOutOfBoundsException()
adjMat[i][j] = 0;
adjMat[j][i] = 0;
adjMat[i][j] = 0
adjMat[j][i] = 0
}
/* 打印邻接矩阵 */
fun print() {
print("顶点列表 = ")
println(vertices);
println("邻接矩阵 =");
println(vertices)
println("邻接矩阵 =")
printMatrix(adjMat)
}
}
@@ -2167,9 +2167,9 @@ comments: true
init {
// 添加所有顶点和边
for (edge in edges) {
addVertex(edge[0]!!);
addVertex(edge[1]!!);
addEdge(edge[0]!!, edge[1]!!);
addVertex(edge[0]!!)
addVertex(edge[1]!!)
addEdge(edge[0]!!, edge[1]!!)
}
}
@@ -2184,7 +2184,7 @@ comments: true
throw IllegalArgumentException()
// 添加边 vet1 - vet2
adjList[vet1]?.add(vet2)
adjList[vet2]?.add(vet1);
adjList[vet2]?.add(vet1)
}
/* 删除边 */
@@ -2192,8 +2192,8 @@ comments: true
if (!adjList.containsKey(vet1) || !adjList.containsKey(vet2) || vet1 == vet2)
throw IllegalArgumentException()
// 删除边 vet1 - vet2
adjList[vet1]?.remove(vet2);
adjList[vet2]?.remove(vet1);
adjList[vet1]?.remove(vet2)
adjList[vet2]?.remove(vet1)
}
/* 添加顶点 */
@@ -2209,7 +2209,7 @@ comments: true
if (!adjList.containsKey(vet))
throw IllegalArgumentException()
// 在邻接表中删除顶点 vet 对应的链表
adjList.remove(vet);
adjList.remove(vet)
// 遍历其他顶点的链表，删除所有包含 vet 的边
for (list in adjList.values) {
list.remove(vet)
docs/chapter_hashing/hash_algorithm.md
+4
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@@ -560,6 +560,7 @@ index = hash(key) % capacity
/* 加法哈希 */
fun addHash(key: String): Int {
var hash = 0L
val MODULUS = 1000000007
for (c in key.toCharArray()) {
hash = (hash + c.code) % MODULUS
}
@@ -569,6 +570,7 @@ index = hash(key) % capacity
/* 乘法哈希 */
fun mulHash(key: String): Int {
var hash = 0L
val MODULUS = 1000000007
for (c in key.toCharArray()) {
hash = (31 * hash + c.code) % MODULUS
}
@@ -578,6 +580,7 @@ index = hash(key) % capacity
/* 异或哈希 */
fun xorHash(key: String): Int {
var hash = 0
val MODULUS = 1000000007
for (c in key.toCharArray()) {
hash = hash xor c.code
}
@@ -587,6 +590,7 @@ index = hash(key) % capacity
/* 旋转哈希 */
fun rotHash(key: String): Int {
var hash = 0L
val MODULUS = 1000000007
for (c in key.toCharArray()) {
hash = ((hash shl 4) xor (hash shr 28) xor c.code.toLong()) % MODULUS
}
docs/chapter_hashing/hash_collision.md
+1 -1
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@@ -1312,7 +1312,7 @@ comments: true
```kotlin title="hash_map_chaining.kt"
/* 链式地址哈希表 */
class HashMapChaining() {
class HashMapChaining {
var size: Int // 键值对数量
var capacity: Int // 哈希表容量
val loadThres: Double // 触发扩容的负载因子阈值
docs/chapter_hashing/hash_map.md
+3 -2
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@@ -1646,7 +1646,8 @@ index = hash(key) % capacity
fun valueSet(): MutableList<String> {
val valueSet = mutableListOf<String>()
for (pair in buckets) {
pair?.let { valueSet.add(it._val) }
if (pair != null)
valueSet.add(pair._val)
}
return valueSet
}
@@ -1656,7 +1657,7 @@ index = hash(key) % capacity
for (kv in pairSet()) {
val key = kv.key
val _val = kv._val
println("${key} -> ${_val}")
println("$key -> $_val")
}
}
}
docs/chapter_heap/build_heap.md
+3 -1
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@@ -220,7 +220,9 @@ comments: true
/* 交换元素 */
private fun swap(i: Int, j: Int) {
maxHeap[i] = maxHeap[j].also { maxHeap[j] = maxHeap[i] }
val temp = maxHeap[i]
maxHeap[i] = maxHeap[j]
maxHeap[j] = temp
}
/* 获取堆大小 */
docs/chapter_heap/heap.md
+1 -1
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@@ -650,7 +650,7 @@ comments: true
/* 获取父节点的索引 */
int parent(MaxHeap *maxHeap, int i) {
return (i - 1) / 2;
return (i - 1) / 2; // 向下取整
}
```
docs/chapter_sorting/bubble_sort.md
+6 -2
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@@ -264,7 +264,9 @@ comments: true
for (j in 0..<i) {
if (nums[j] > nums[j + 1]) {
// 交换 nums[j] 与 nums[j + 1]
nums[j] = nums[j + 1].also { nums[j + 1] = nums[j] }
val temp = nums[j]
nums[j] = nums[j + 1]
nums[j + 1] = temp
}
}
}
@@ -571,7 +573,9 @@ comments: true
for (j in 0..<i) {
if (nums[j] > nums[j + 1]) {
// 交换 nums[j] 与 nums[j + 1]
nums[j] = nums[j + 1].also { nums[j] = nums[j + 1] }
val temp = nums[j]
nums[j] = nums[j + 1]
nums[j + 1] = temp
flag = true // 记录交换元素
}
}
docs/chapter_sorting/heap_sort.md
+6 -2
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@@ -553,7 +553,9 @@ comments: true
if (ma == i)
break
// 交换两节点
nums[i] = nums[ma].also { nums[ma] = nums[i] }
val temp = nums[i]
nums[i] = nums[ma]
nums[ma] = temp
// 循环向下堆化
i = ma
}
@@ -568,7 +570,9 @@ comments: true
// 从堆中提取最大元素，循环 n-1 轮
for (i in nums.size - 1 downTo 1) {
// 交换根节点与最右叶节点（交换首元素与尾元素）
nums[0] = nums[i].also { nums[i] = nums[0] }
val temp = nums[0]
nums[0] = nums[i]
nums[i] = temp
// 以根节点为起点，从顶至底进行堆化
siftDown(nums, i, 0)
}
docs/chapter_sorting/quick_sort.md
+3 -1
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@@ -328,7 +328,9 @@ comments: true
```kotlin title="quick_sort.kt"
/* 元素交换 */
fun swap(nums: IntArray, i: Int, j: Int) {
nums[i] = nums[j].also { nums[j] = nums[i] }
val temp = nums[i]
nums[i] = nums[j]
nums[j] = temp
}
/* 哨兵划分 */
docs/chapter_sorting/selection_sort.md
+3 -1
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@@ -296,7 +296,9 @@ comments: true
k = j // 记录最小元素的索引
}
// 将该最小元素与未排序区间的首个元素交换
nums[i] = nums[k].also { nums[k] = nums[i] }
val temp = nums[i]
nums[i] = nums[k]
nums[k] = temp
}
}
```
docs/chapter_stack_and_queue/stack.md
+1 -1
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@@ -1092,7 +1092,7 @@ comments: true
fun pop(): Int? {
val num = peek()
stackPeek = stackPeek?.next
stkSize--;
stkSize--
return num
}
docs/chapter_tree/array_representation_of_tree.md
+2 -2
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@@ -125,7 +125,7 @@ comments: true
```kotlin title=""
/* 二叉树的数组表示 */
// 使用 null 来表示空位
val tree = mutableListOf( 1, 2, 3, 4, null, 6, 7, 8, 9, null, null, 12, null, null, 15 )
val tree = arrayOf( 1, 2, 3, 4, null, 6, 7, 8, 9, null, null, 12, null, null, 15 )
```
=== "Ruby"
@@ -1172,7 +1172,7 @@ comments: true
=== "Kotlin"
```kotlin title="array_binary_tree.kt"
/* 构造方法 */
/* 数组表示下的二叉树类 */
class ArrayBinaryTree(val tree: MutableList<Int?>) {
/* 列表容量 */
fun size(): Int {
docs/chapter_tree/binary_tree_traversal.md
+1 -1
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@@ -305,7 +305,7 @@ comments: true
val list = mutableListOf<Int>()
while (queue.isNotEmpty()) {
val node = queue.poll() // 队列出队
list.add(node?._val!!) // 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)