update 1.two_sum.java

Author: marklcrns

1.two_sum.java

@@ -1,3 +1,58 @@
+/*
+ * @lc app=leetcode id=1 lang=java
+ *
+ * [1] Two Sum
+ *
+ * https://leetcode.com/problems/two-sum/description/
+ *
+ * algorithms
+ * Easy (46.11%)
+ * Total Accepted:    3.7M
+ * Total Submissions: 8M
+ * Testcase Example:  '[2,7,11,15]\n9'
+ *
+ * Given an array of integers nums and an integer target, return indices of the
+ * two numbers such that they add up to target.
+ *
+ * You may assume that each input would have exactly one solution, and you may
+ * not use the same element twice.
+ *
+ * You can return the answer in any order.
+ *
+ *
+ * Example 1:
+ *
+ *
+ * Input: nums = [2,7,11,15], target = 9
+ * Output: [0,1]
+ * Output: Because nums[0] + nums[1] == 9, we return [0, 1].
+ *
+ *
+ * Example 2:
+ *
+ *
+ * Input: nums = [3,2,4], target = 6
+ * Output: [1,2]
+ *
+ *
+ * Example 3:
+ *
+ *
+ * Input: nums = [3,3], target = 6
+ * Output: [0,1]
+ *
+ *
+ *
+ * Constraints:
+ *
+ *
+ * 2 <= nums.length <= 10^3
+ * -10^9 <= nums[i] <= 10^9
+ * -10^9 <= target <= 10^9
+ * Only one valid answer exists.
+ *
+ *
+ */
 class Solution {
     public int[] twoSum(int[] nums, int target) {
         int[] result = new int[2];