From 355ac4393b44c87589dc01e4441fea0c2a04192c Mon Sep 17 00:00:00 2001
From: zerosaturation <zerosaturation@163.com>
Date: Wed, 1 Jul 2026 12:45:17 +0800
Subject: [PATCH] =?UTF-8?q?feat=EF=BC=9A=E4=BF=AE=E6=94=B9=E6=94=B6?=
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---
 .../taskService/service/revenue_service.go      | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/backend/services/taskService/service/revenue_service.go b/backend/services/taskService/service/revenue_service.go
index 7292c4b..d29e067 100644
--- a/backend/services/taskService/service/revenue_service.go
+++ b/backend/services/taskService/service/revenue_service.go
@@ -425,6 +425,19 @@ func CalculateBuff(likeCount int) int {
 	}
 }
 
+// roundHalfToEven 银行家四舍五入（round half to even）
+// 当小数部分恰好为 0.5 时，向最近的偶数舍入，避免统计偏差
+// 例如：2.5 → 2, 3.5 → 4, 4.5 → 4, 5.5 → 6
+func roundHalfToEven(numerator, denominator int64) int64 {
+	quotient := numerator / denominator
+	remainder := numerator % denominator
+	half := denominator / 2
+	if remainder > half || (remainder == half && quotient%2 != 0) {
+		quotient++
+	}
+	return quotient
+}
+
 // CalculateExhibitionRevenue 计算单次上架收益（参考实现，未被调用）
 // 注意：实际收益计算在 OnExhibitionCompleted 中通过 AssetLevelService.CalculateRevenue 实现
 // 此函数保留用于参考和测试场景
@@ -449,9 +462,9 @@ func CalculateExhibitionRevenue(likeCount int, startTime, endTime int64, revenue
 	// 基础收益
 	baseRevenue := R0 * T
 
-	// 应用Buff加成
+	// 应用Buff加成（银行家四舍五入）
 	// R1 = R0 × T × (100% + Buff)
-	buffedRevenue := baseRevenue * (100 + int64(buff)) / 100
+	buffedRevenue := roundHalfToEven(baseRevenue*(100+int64(buff)), 100)
 
 	// 应用永久收益提升
 	if revenueBoostBps > 0 {