fix:bug

services/red_envelope/red_envelop.go

@@ -51,14 +51,19 @@ const (
 )
 
 func GenRedPack(amount, num int) []int {
-	r := rand.New(rand.NewSource(time.Now().Unix()))
 	sumMoney := 0
 	redPacks := make([]int, 0)
+	maxMoney := MaxRedPackAmount
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
 	for i := 0; i < num; i++ {
-		money := r.Int() * 2 * (amount - sumMoney) / (num - i)
-		if money <= MinRedPackAmount {
+		maxMoney = (amount - sumMoney) / (num - i)
+		if maxMoney > MaxRedPackAmount {
+			maxMoney = MaxRedPackAmount
+		}
+		money := r.Int()
+		if money < MinRedPackAmount {
 			money = MinRedPackAmount
-		} else if money >= MaxRedPackAmount {
+		} else if money > MaxRedPackAmount {
 			money = MaxRedPackAmount
 		}
 
@@ -88,16 +93,24 @@ func GenRedEnvelope(aid int64, name string, rid int64, rule *models.ShakeRedEnve
 		// 检测红包是否存在
 		randSum := int(rule.RandSum * 100)
 		sumMoney := 0
-		if randSum/rule.RedEnvelopeNum > MinRedPackAmount && randSum/rule.RedEnvelopeNum < MaxRedPackAmount {
+		maxMoney := MaxRedPackAmount
+		if randSum/rule.RedEnvelopeNum <= MinRedPackAmount && randSum/rule.RedEnvelopeNum >= MaxRedPackAmount {
 			return errors.New("每个红包的平均金额必须在1.00元到200.00元之间")
 		}
 		for i := 0; i < rule.RedEnvelopeNum; i++ {
-			money := r.Int() * 2 * (randSum - sumMoney) / (rule.RedEnvelopeNum - i)
-			if money <= MinRedPackAmount { // 随机的金额可能小于1块钱
+			// 前置判断每次循环是否存在最小值
+			//最大可领金额 = 剩余金额的平均值x2 = (剩余金额 / 剩余数量) * 2
+			maxMoney = (randSum - sumMoney) / (rule.RedEnvelopeNum - i)
+			if maxMoney > MaxRedPackAmount {
+				maxMoney = MaxRedPackAmount
+			}
+			money := r.Intn(maxMoney)
+			if money < MinRedPackAmount { // 随机的金额可能小于1块钱
 				money = MinRedPackAmount
-			} else if money >= MaxRedPackAmount {
+			} else if money > MaxRedPackAmount {
 				money = MaxRedPackAmount
 			}
+
 			// 提前预判剩余红包和红包的金额比例 ==> money/num <= 0.01
 			rate := (randSum - sumMoney - money) / (rule.RedEnvelopeNum - i)
 			if rate <= MinRedPackAmount {