149 lines
2.5 KiB
Go
149 lines
2.5 KiB
Go
package rand
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import (
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"github.com/tx7do/go-utils/math"
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"math/rand"
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)
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var rnd = rand.New(rand.NewSource(Seed(UnixNanoSeed)))
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func init() {
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if rnd != nil {
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rnd = rand.New(rand.NewSource(Seed(UnixNanoSeed)))
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}
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}
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func Float32() float32 {
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return rnd.Float32()
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}
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func Float64() float64 {
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return rnd.Float64()
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}
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func Intn(n int) int {
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return rnd.Intn(n)
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}
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func Int31n(n int32) int32 {
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return rnd.Int31n(n)
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}
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func Int63n(n int64) int64 {
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return rnd.Int63n(n)
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}
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// RandomInt 根据区间产生随机数
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func RandomInt(min, max int) int {
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if min >= max {
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return max
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}
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return min + Intn(max-min+1)
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}
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// RandomInt32 根据区间产生随机数
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func RandomInt32(min, max int32) int32 {
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if min >= max {
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return max
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}
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return min + Int31n(max-min+1)
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}
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// RandomInt64 根据区间产生随机数
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func RandomInt64(min, max int64) int64 {
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if min >= max {
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return max
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}
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return min + Int63n(max-min+1)
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}
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// RandomString 随机字符串，包含大小写字母和数字
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func RandomString(l int) string {
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if l <= 0 {
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return ""
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}
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const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
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bytes := make([]byte, l)
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for i := 0; i < l; i++ {
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bytes[i] = charset[Intn(len(charset))]
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}
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return string(bytes)
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}
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// RandomChoice 随机选择数组中的元素
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func RandomChoice[T any](array []T, n int) []T {
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if n <= 0 {
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return nil
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}
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if n == 1 {
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return []T{array[Intn(len(array))]}
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}
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tmp := make([]T, len(array))
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copy(tmp, array)
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if len(tmp) <= n {
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return tmp
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}
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Shuffle(tmp)
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return tmp[:n]
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}
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// Shuffle 随机打乱数组
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func Shuffle[T any](array []T) {
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if array == nil {
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return
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}
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for i := range array {
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j := Intn(i + 1)
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array[i], array[j] = array[j], array[i]
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}
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}
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// WeightedChoice 根据权重随机，返回对应选项的索引，O(n)
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func WeightedChoice(weightArray []int) int {
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if weightArray == nil {
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return -1
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}
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total := math.SumInt(weightArray)
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rv := Int63n(total)
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for i, v := range weightArray {
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if rv < int64(v) {
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return i
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}
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rv -= int64(v)
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}
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return len(weightArray) - 1
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}
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// NonWeightedChoice 根据权重随机，返回对应选项的索引，O(n). 权重大于等于0
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func NonWeightedChoice(weightArray []int) int {
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if weightArray == nil {
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return -1
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}
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for i, weight := range weightArray {
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if weight < 0 {
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weightArray[i] = 0
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}
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}
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total := math.SumInt(weightArray)
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rv := Int63n(total)
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for i, v := range weightArray {
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if rv < int64(v) {
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return i
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}
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rv -= int64(v)
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}
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return len(weightArray) - 1
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}
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