add 001

Author: andavid

README.md

@@ -21,9 +21,9 @@
 | 217  | [Contains Duplicate][217]                   |
 | 136  | [Single Number][136]                        |
 | 350  | [Intersection of Two Arrays II][350]        |
-| 66   | [Plus One][066]                              |
+| 66   | [Plus One][066]                             |
 | 283  | [Move Zeroes][283]                          |
-
+| 1    | [Two Sum][001]                              |
 
 **其他**
 
@@ -46,3 +46,4 @@
 [350]: https://github.com/andavid/leetcode-java/blob/master/note/350/README.md
 [066]: https://github.com/andavid/leetcode-java/blob/master/note/066/README.md
 [283]: https://github.com/andavid/leetcode-java/blob/master/note/283/README.md
+[001]: https://github.com/andavid/leetcode-java/blob/master/note/001/README.md

note/001/README.md

@@ -0,0 +1,16 @@
+# [xxx][title]
+
+## Description
+
+
+## 思路
+
+
+## [完整代码][src]
+
+```java
+
+```
+
+[title]: https://leetcode.com/problems/xxx
+[src]: https://github.com/andavid/leetcode-java/blob/master/src/com/andavid/leetcode/_xxx/Solution.java

src/com/andavid/leetcode/_001/Solution.java

@@ -0,0 +1,30 @@
+import java.util.*;
+
+class Solution {
+  public int[] twoSum(int[] nums, int target) {
+    if (nums == null || nums.length < 2) {
+      return null;
+    }
+
+    Map<Integer, Integer> map = new HashMap<>();
+    for (int i = 0; i < nums.length; i++) {
+      if (map.containsKey(target - nums[i])) {
+        int[] result = new int[2];
+        result[0] = map.get(target - nums[i]);
+        result[1] = i;
+        return result;
+      }
+      map.put(nums[i], i);
+    }
+
+    return null;
+  }
+
+  public static void main(String[] args) {
+    Solution solution = new Solution();
+    int[] nums = solution.twoSum(new int[]{2, 7, 11, 15}, 9);
+    for (int i = 0; i < nums.length; i++) {
+      System.out.print(i == 0 ? nums[i] : "," + nums[i]);
+    }
+  }
+}