Merge pull request #1696 from casnz1601/patch-29

Update 0001.两数之和.md

problems/0001.两数之和.md

@@ -152,25 +152,11 @@ class Solution:
     def twoSum(self, nums: List[int], target: int) -> List[int]:
         records = dict()
 
-        # 用枚举更方便，就不需要通过索引再去取当前位置的值
-        for idx, val in enumerate(nums):
-            if target - val not in records:
-                records[val] = idx
-            else:
-                return [records[target - val], idx] # 如果存在就返回字典记录索引和当前索引
-```
-
-Python (v2):
-
-```python
-class Solution:
-    def twoSum(self, nums: List[int], target: int) -> List[int]:
-        rec = {}
-        for i in range(len(nums)):
-            rest = target - nums[i]
-            # Use get to get the index of the data, making use of one of the dictionary properties.
-            if rec.get(rest, None) is not None: return [rec[rest], i]
-            rec[nums[i]] = i
+        for index, value in enumerate(nums):
+            if target - value in records:
+                return [records[target- value], index]
+            records[value] = index
+        return []
 ```
 
 Go：