diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 00000000..7794435b
Binary files /dev/null and b/.DS_Store differ
diff --git a/problems/0494.目标和.md b/problems/0494.目标和.md
index 0faef4a5..f190b734 100644
--- a/problems/0494.目标和.md
+++ b/problems/0494.目标和.md
@@ -272,7 +272,8 @@ Python：
 class Solution:
     def findTargetSumWays(self, nums: List[int], target: int) -> int:
         sumValue = sum(nums)
-        if target > sumValue or (sumValue + target) % 2 == 1: return 0
+        #注意边界条件为 target>sumValue or target<-sumValue or  (sumValue + target) % 2 == 1
+        if abs(target) > sumValue or (sumValue + target) % 2 == 1: return 0
         bagSize = (sumValue + target) // 2
         dp = [0] * (bagSize + 1)
         dp[0] = 1