From d9d0392db39cff582d1af1e78286d62570bb1979 Mon Sep 17 00:00:00 2001
From: kercylan98 <kercylan@gmail.com>
Date: Wed, 2 Aug 2023 15:10:32 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20random=20=E5=8C=85=E6=96=B0=E5=A2=9E=20?=
 =?UTF-8?q?Dice=20=E6=8E=B7=E9=AA=B0=E5=AD=90=E5=92=8C=20Probability=20?=
 =?UTF-8?q?=E6=A6=82=E7=8E=87=E5=87=BD=E6=95=B0?=
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---
 utils/random/dice.go        | 16 ++++++++++++++++
 utils/random/probability.go | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 utils/random/dice.go
 create mode 100644 utils/random/probability.go

diff --git a/utils/random/dice.go b/utils/random/dice.go
new file mode 100644
index 0000000..3d23842
--- /dev/null
+++ b/utils/random/dice.go
@@ -0,0 +1,16 @@
+package random
+
+// Dice 掷骰子
+//   - 常规掷骰子将返回 1-6 的随机数
+func Dice() int {
+	return Int(1, 6)
+}
+
+// DiceN 掷骰子
+//   - 与 Dice 不同的是，将返回 1-N 的随机数
+func DiceN(n int) int {
+	if n <= 1 {
+		return 1
+	}
+	return Int(1, n)
+}
diff --git a/utils/random/probability.go b/utils/random/probability.go
new file mode 100644
index 0000000..a9763ab
--- /dev/null
+++ b/utils/random/probability.go
@@ -0,0 +1,36 @@
+package random
+
+// Probability 输入一个概率，返回是否命中
+//   - 当 full 不为空时，将以 full 为基数，p 为分子，计算命中概率
+func Probability(p int, full ...int) bool {
+	var f = 100
+	if len(full) > 0 {
+		f = full[0]
+		if f <= 0 {
+			f = 100
+		} else if p > f {
+			return true
+		}
+	}
+	r := Int(1, f)
+	return r <= p
+}
+
+// ProbabilityChooseOne 输入一组概率，返回命中的索引
+func ProbabilityChooseOne(ps ...int) int {
+	var f int
+	for _, p := range ps {
+		f += p
+	}
+	if f <= 0 {
+		panic("total probability less than or equal to 0")
+	}
+	r := Int(1, f)
+	for i, p := range ps {
+		if r <= p {
+			return i
+		}
+		r -= p
+	}
+	panic("probability choose one error")
+}