思路2 排序+双指针 （不推荐，时间复杂度O (nlogn),空间复杂度O (1)） 这种解法的时间复杂度为 O (nlogn)，空间复杂度为 O (1)。相比于暴力 枚举法，它显然更加高效。但是需要注意的是，这种解法 …

So, if we fix one of the numbers, say x, we have to scan the entire array to find the next number y which is value - x where value is the input parameter. Can we change our array somehow so that this …

Dec 30, 2025 · 解法概览 解法1：暴力法 在leetcode中运行用时: 65 ms, 在Two Sum的 Java 提交中击败了19.51% 的用户 复杂度分析： 时间复杂度：O (n^2) 空间复杂度：O (1)。 解法思路：按大神的推 …

You may assume that *every* input has exactly one pair of indices `i` and `j` that satisfy the condition. Return the answer with the smaller index first. **Example 1:** ```java Input: nums = [3,4,5,6], target = …

Jul 23, 2025 · The 2-Sum problem is a popular algorithmic challenge where the goal is to identify two distinct elements in an array whose sum equals a specific target. The problem emphasizes …

Java solutions for LeetCode’s Two Sum problem. One sticks to basic loops, the other uses a HashMap. Both are great for getting ready for interview prep.

About Solved the classic Two Sum problem using Java, including both brute force and optimized hash-based approaches.

leetCode:twoSum 两数之和 【JAVA实现】 LeetCode 两数之和 给定一个整数数组，返回两个数字的索引，使它们相加到特定目标。 您可以假设每个输入只有一个解决方案，并且您可能不会两次使用相 …

Feb 14, 2023 · Explore and compare three solutions to the Two Sum Problem on LeetCode using Java. Choose the most optimal approach for time and space complexity.

Jan 13, 2026 · Solving LeetCode’s Two Sum in Java. Last updated January 13, 2026. This is part of our LeetCode Beginners Java Course. Start solving algorithmic challenges today, or build your …