diff --git a/problems/0494.目标和.md b/problems/0494.目标和.md
index 1a4dda2b..2d38b4d0 100644
--- a/problems/0494.目标和.md
+++ b/problems/0494.目标和.md
@@ -275,19 +275,23 @@ class Solution {
     public int findTargetSumWays(int[] nums, int target) {
         int sum = 0;
         for (int i = 0; i < nums.length; i++) sum += nums[i];
-	//如果target过大 sum将无法满足
-        if ( target < 0 && sum < -target) return 0;
-        if ((target + sum) % 2 != 0) return 0;
-        int size = (target + sum) / 2;
-        if(size < 0) size = -size;
-        int[] dp = new int[size + 1];
+
+        //如果target的绝对值大于sum，那么是没有方案的
+        if (Math.abs(target) > sum) return 0;
+        //如果(target+sum)除以2的余数不为0，也是没有方案的
+        if ((target + sum) % 2 == 1) return 0;
+
+        int bagSize = (target + sum) / 2;
+        int[] dp = new int[bagSize + 1];
         dp[0] = 1;
+
         for (int i = 0; i < nums.length; i++) {
-            for (int j = size; j >= nums[i]; j--) {
+            for (int j = bagSize; j >= nums[i]; j--) {
                 dp[j] += dp[j - nums[i]];
             }
         }
-        return dp[size];
+
+        return dp[bagSize];
     }
 }
 ```