Update 0494.目标和.md

java代码部分无法通过leetcode提交,需要先判断sum是否可以满足target

problems/0494.目标和.md

@@ -270,6 +270,8 @@ 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;