ADD: math.A && math.C

app.go

@@ -1,6 +1,6 @@
 /*
  * @Author: NorthCity1984
- * @LastEditTime: 2022-04-02 13:19:42
+ * @LastEditTime: 2022-05-03 18:51:46
  * @Description:
  * @Website: https://grimoire.cn
  * Copyright (c) NorthCity1984 All rights reserved.
@@ -10,28 +10,18 @@ package main
 import (
 	"fmt"
 
-	"gitee.com/NorthCityChen/stl-go/dequeue"
+	"gitee.com/NorthCityChen/stl-go/math"
 )
 
+var a = []int{1, 2, 65, 4, 33, 5}
+
 func main() {
-	q := dequeue.Init[int]()
-	q.LPush(12)
-	q.LPush(23)
-	q.LPush(34)
-	q.Clear()
-	q.LPush(34)
-	q.RPush(44)
-	fmt.Println(q.LPop())
-	fmt.Println(q.LPop())
-	fmt.Println(q.LPop())
-	fmt.Println(q.LPop())
-	// q := queue.Init[int]()
-	// q.Push(12)
-	// q.Push(23)
-	// q.Push(44)
-	// // q.IsEmpty()
-	// fmt.Println(q.Pop())
-	// fmt.Println(q.Pop())
-	// fmt.Println(q.Pop())
-	// fmt.Println(q.Pop())
+	// h := heap.Init(a, heap.MinHeap[int]())
+	// fmt.Println(h)
+
+	ans := math.C(8, 2)
+	fmt.Println(ans)
+
+	ans = math.A(12, 2)
+	fmt.Println(ans)
 }

bit/bit.go

@@ -0,0 +1,55 @@
+/*
+ * @Author: NorthCity1984
+ * @LastEditTime: 2022-04-26 17:08:18
+ * @Description: Binary Indexed Trees
+ * @Website: https://grimoire.cn
+ * Copyright (c) NorthCity1984 All rights reserved.
+ */
+
+package bit
+
+type Number interface {
+	int | int64 | float32 | float64
+}
+
+type bit[T Number] struct {
+	array []T
+	brray []T
+	len   int
+}
+
+func lowbit(x int) int {
+	return x & -x
+}
+
+// 初始化一个树状数组
+func Init[T Number](array []T) bit[T] {
+	ret := bit[T]{
+		array: append([]T{0}, array...),
+		brray: make([]T, len(array)+5),
+		len:   len(array),
+	}
+
+	for i := 1; i < len(ret.array); i++ {
+		ret.Add(i, ret.array[i])
+	}
+	return ret
+}
+
+// 在第x个数的位置+k
+func (b *bit[T]) Add(x int, k T) {
+	for x <= b.len {
+		b.brray[x] = b.brray[x] + k
+		x = x + lowbit(x) // 父节点
+	}
+}
+
+// 求第一个数到第x个数的和
+func (b *bit[T]) Ask(x int) T {
+	var ans T = 0
+	for x >= 1 {
+		ans = ans + b.brray[x]
+		x = x - lowbit(x)
+	}
+	return ans
+}

dequeue/dequeue.go

@@ -1,6 +1,6 @@
 /*
  * @Author: NorthCity1984
- * @LastEditTime: 2022-04-02 12:39:15
+ * @LastEditTime: 2022-04-27 13:31:14
  * @Description:
  * @Website: https://grimoire.cn
  * Copyright (c) NorthCity1984 All rights reserved.
@@ -8,7 +8,7 @@
 package dequeue
 
 type Number interface {
-	int | int64 | float32 | float64
+	int | int64 | float32 | float64 | string
 }
 
 // dequeue: Based on Double Linked List
@@ -24,6 +24,9 @@ type dequeueNode[T Number] struct {
 	RPointer *dequeueNode[T]
 }
 
+// 返回对应类型的零值 对比 T(Rune(0))在获取空字符串的情况下快14倍左右
+func zeroValue[T Number]() (value T) { return }
+
 func Init[T Number]() *Dequeue[T] {
 	return &Dequeue[T]{size: 0, leftHead: new(dequeueNode[T]), rightHead: new(dequeueNode[T])}
 }
@@ -50,7 +53,7 @@ func (q *Dequeue[T]) LPush(val T) bool {
 
 func (q *Dequeue[T]) LPop() (T, bool) {
 	if q.IsEmpty() {
-		return 0, false
+		return zeroValue[T](), false
 	}
 	val := q.leftHead.Val
 	q.leftHead = q.leftHead.RPointer
@@ -72,7 +75,7 @@ func (q *Dequeue[T]) RPush(val T) bool {
 
 func (q *Dequeue[T]) RPop() (T, bool) {
 	if q.IsEmpty() {
-		return 0, false
+		return zeroValue[T](), false
 	}
 	val := q.rightHead.Val
 	q.rightHead = q.rightHead.LPointer
@@ -82,14 +85,14 @@ func (q *Dequeue[T]) RPop() (T, bool) {
 
 func (q *Dequeue[T]) LNode() (T, bool) {
 	if q.IsEmpty() {
-		return 0, false
+		return zeroValue[T](), false
 	}
 	return q.leftHead.Val, true
 }
 
 func (q *Dequeue[T]) RNode() (T, bool) {
 	if q.IsEmpty() {
-		return 0, false
+		return zeroValue[T](), false
 	}
 	return q.rightHead.Val, true
 }

dequeue/dequeue_test.go

@@ -0,0 +1,50 @@
+/*
+ * @Author: NorthCity1984
+ * @LastEditTime: 2022-04-27 13:36:25
+ * @Description:
+ * @Website: https://grimoire.cn
+ * Copyright (c) NorthCity1984 All rights reserved.
+ */
+package dequeue
+
+import (
+	"testing"
+	// "gitee.com/NorthCityChen/stl-go/dequeue"
+)
+
+// type Number interface {
+// 	int | int64 | float32 | float64 | string
+// }
+
+// func zeroValue[T Number]() (value T) { return }
+func TRune[T Number]() T { return T(rune(0)) }
+
+func BenchmarkZeroValue(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		zeroValue[float64]()
+		zeroValue[float32]()
+		zeroValue[int]()
+		zeroValue[int64]()
+		zeroValue[string]()
+	}
+}
+
+func BenchmarkTRune(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		TRune[float64]()
+		TRune[float32]()
+		TRune[int64]()
+		TRune[int]()
+		TRune[string]()
+	}
+}
+
+func BenchmarkRunDequeue(b *testing.B) {
+	dq := Init[int]()
+	for i := 0; i < b.N; i++ {
+		dq.LPush(1)
+		dq.RPush(2)
+		dq.LPop()
+		dq.RPop()
+	}
+}

heap/heap.go

@@ -0,0 +1,90 @@
+/*
+ * @Author: NorthCity1984
+ * @LastEditTime: 2022-04-27 13:19:36
+ * @Description:
+ * @Website: https://grimoire.cn
+ * Copyright (c) NorthCity1984 All rights reserved.
+ */
+package heap
+
+type Number interface {
+	int | int64 | float32 | float64
+}
+
+type heap[T Number] struct {
+	array []T
+	len   int
+	cmp   func(T, T) bool
+}
+
+// 返回对应类型的零值
+func zeroValue[T Number]() (value T) { return }
+
+func (h *heap[T]) up(x int) {
+	for x > 1 && h.cmp(h.array[x], h.array[x/2]) {
+		h.array[x], h.array[x/2] = h.array[x/2], h.array[x]
+		x /= 2
+	}
+}
+
+func (h *heap[T]) down(x int) {
+	for x*2 <= h.len {
+		t := x * 2
+		if t+1 <= h.len && h.cmp(h.array[t+1], h.array[t]) {
+			t++
+		}
+		if !h.cmp(h.array[t], h.array[x]) {
+			break
+		}
+		h.array[x], h.array[t] = h.array[t], h.array[x]
+		x = t
+	}
+}
+
+func (h *heap[T]) Push(v T) {
+	h.array = append(h.array, v)
+	h.len++
+	h.up(h.len)
+}
+
+func (h *heap[T]) Pop() T {
+	if h.len == 0 {
+		return zeroValue[T]()
+	}
+	ret := h.array[1]
+	h.array[1], h.array[h.len] = h.array[h.len], h.array[1]
+	h.array = h.array[:h.len]
+	h.len--
+	h.down(1)
+	return ret
+}
+
+func (h *heap[T]) Top() T {
+	return h.array[1]
+}
+
+func Init[T Number](array []T, cmp func(T, T) bool) heap[T] {
+	newArray := make([]T, len(array)+1)
+	copy(newArray[1:], array)
+	h := heap[T]{
+		array: newArray,
+		len:   len(array),
+		cmp:   cmp,
+	}
+	for i := h.len; i >= 1; i-- {
+		h.down(i)
+	}
+	return h
+}
+
+func MaxHeap[T Number]() func(T, T) bool {
+	return func(t1, t2 T) bool {
+		return t1 > t2
+	}
+}
+
+func MinHeap[T Number]() func(T, T) bool {
+	return func(t1, t2 T) bool {
+		return t1 < t2
+	}
+}

math/math.go

@@ -1,6 +1,6 @@
 /*
  * @Author: NorthCity1984
- * @LastEditTime: 2022-04-01 21:04:53
+ * @LastEditTime: 2022-05-03 18:50:22
  * @Description:
  * @Website: https://grimoire.cn
  * Copyright (c) NorthCity1984 All rights reserved.
@@ -13,10 +13,7 @@ type Number interface {
 	int | int32 | int64 | float32 | float64
 }
 
-func Inf[T Number]() T {
-	return T(math.Inf(1))
-}
-
+// 返回n个数中的最小值
 func Max[T Number](arg T, args ...T) T {
 	var maxNum T = arg
 
@@ -28,6 +25,7 @@ func Max[T Number](arg T, args ...T) T {
 	return maxNum
 }
 
+// 返回n个数中的最大值
 func Min[T Number](arg T, args ...T) T {
 	var minNum T = arg
 	for _, val := range args {
@@ -38,6 +36,7 @@ func Min[T Number](arg T, args ...T) T {
 	return minNum
 }
 
+// 返回n个数的和
 func Sum[T Number](args ...T) (sum T) {
 	for _, val := range args {
 		sum += val
@@ -45,6 +44,7 @@ func Sum[T Number](args ...T) (sum T) {
 	return sum
 }
 
+// 返回num的绝对值
 func Abs[T Number](num T) T {
 	if num < 0 {
 		num *= -1
@@ -52,4 +52,46 @@ func Abs[T Number](num T) T {
 	return num
 }
 
-// sort
+// 返回 2**n
+func Exp2(num int) int64 {
+	var ans int64 = 1
+	for i := 0; i < num; i++ {
+		ans <<= 1
+	}
+	return ans
+}
+
+// 返回x的平方根，精度比原生略低
+func Sqrt(x float64) float64 {
+	if x < 0 {
+		return math.NaN()
+	}
+
+	if x == 0 {
+		return 0
+	}
+	last, res := 0.0, 1.0
+	for last != res {
+		last = res
+		res = (res + x/res) / 2
+	}
+	return res
+}
+
+// 排列数： A(3,1)=3
+func A(n, m int) int {
+	res := 1
+	for i := m; i >= 1; i-- {
+		res *= n //n × n-1 × n-2 × ... n-m，m就是需要减1的次数
+		n--
+	}
+	return res
+}
+
+// 组合数：C(3, 2)=3
+func C(n, m int) int {
+	if m == 0 {
+		return 1
+	}
+	return C(n-1, m-1) * (n / m)
+}

random/random.go

@@ -0,0 +1,40 @@
+/*
+ * @Author: NorthCity1984
+ * @LastEditTime: 2022-04-04 19:11:44
+ * @Description:
+ * @Website: https://grimoire.cn
+ * Copyright (c) NorthCity1984 All rights reserved.
+ */
+package random
+
+import (
+	"math/rand"
+	"strings"
+	"time"
+)
+
+const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+const (
+	letterIdxBits = 6                    // 6 bits to represent a letter index
+	letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
+	letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
+)
+
+var src = rand.NewSource(time.Now().UnixNano())
+
+func RandStr(strLen int) string {
+	str := strings.Builder{}
+	str.Grow(strLen)
+	for i, cache, remain := strLen-1, src.Int63(), letterIdxMax; i >= 0; {
+		if remain == 0 {
+			cache, remain = src.Int63(), letterIdxMax
+		}
+		if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
+			str.WriteByte(letterBytes[idx])
+			i--
+		}
+		cache >>= letterIdxBits
+		remain--
+	}
+	return str.String()
+}

readme.md

@@ -1,10 +1,72 @@
 <!--
  * @Author: NorthCity1984
- * @LastEditTime: 2022-04-01 13:22:46
+ * @LastEditTime: 2022-04-02 14:30:28
  * @Description: 
  * @Website: https://grimoire.cn
  * Copyright (c) NorthCity1984 All rights reserved.
 -->
 # stl-go
 
-一些常用的数据结构模板
+一个封装了一些简单的数据结构的提供泛型支持的stl库 (go >= 1.18)
+
+# usage
+
+## Dequeue
+
+```go
+package main
+
+import (
+	"fmt"
+
+	"gitee.com/NorthCityChen/stl-go/dequeue"
+)
+
+func main() {
+	q := dequeue.Init[int]()
+	q.LPush(12)
+	q.LPush(23)
+	q.LPush(34)
+	q.Clear()
+	q.LPush(34)
+	q.RPush(44)
+	fmt.Println(q.LPop())
+	fmt.Println(q.LPop())
+	fmt.Println(q.LPop())
+	fmt.Println(q.LPop())
+}
+```
+
+## Queue
+
+```go
+import (
+	"fmt"
+
+	"gitee.com/NorthCityChen/stl-go/queue"
+)
+
+func main() {
+	q := queue.Init[int]()
+	q.Push(12)
+	q.Push(23)
+	q.Push(44)
+	fmt.Println(q.Pop())
+	fmt.Println(q.Pop())
+	fmt.Println(q.Pop())
+	fmt.Println(q.Pop())
+}
+
+```
+
+# RoadMap
+
+- [x] 双端队列
+- [x] 队列
+- [x] 栈
+- [x] 数学
+- [ ] 优先队列
+- [ ] 红黑树
+- [ ] 集合
+- [ ] 二分查找
+- [ ] 下一个排序组合

stack/stack.go

@@ -1,6 +1,6 @@
 /*
  * @Author: NorthCity1984
- * @LastEditTime: 2022-04-02 13:19:33
+ * @LastEditTime: 2022-04-13 21:41:20
  * @Description:
  * @Website: https://grimoire.cn
  * Copyright (c) NorthCity1984 All rights reserved.