问题

我是LeetCode的新手，在尝试运行我的代码时一直遇到错误。有人之前遇到过这种情况吗？我已经尝试了许多不同的方法，甚至使用了别人的代码，而那些代码是可以正常工作的。

```java
class Solution {
   public int[] twoSum(int[] nums, int target) {         
       for (int i = 0; i < nums.length; i++) {
           for (int j = i + 1; j < nums.length; j++) {
               int complement = target - nums[i];
               if (nums[j] == complement) {
                   return new int[] {i, j};
                }
            }
        }
            
        throw new IllegalArgumentException("找不到匹配");
    }
}

这是我的代码。有人能帮帮我吗？

<details>
<summary>英文:</summary>

I am new on LeetCode, and continue to get an error when trying to run my code. Has anyone encountered this before. I have tried many different methods and even used other peoples code that has worked. 

```java
class Solution {
   public int[] twoSum(int[] nums, int target) {         
       for (int i = 0; i &lt; nums.length; i++) {
           for (int j = i + 1; j &lt; nums.length; j++) {
               int complement = target - nums[i];
               if (nums[j] == complement) {
                   return new int[] {i, j};
                }
            }
        }
            
        throw new IllegalArgumentException(&quot;no match found&quot;);
    }
}

<!-- end snippet -->

This is my code. Can anyone help me?

答案1

得分: 1

你的代码已经很好了，不过我们可以使用 HashMap 来更高效地解决这个问题：

public class Solution {
    public static final int[] twoSum(
        final int[] nums, 
        final int target
    ) {
        int[] indices = new int[2];
        HashMap<Integer, Integer> map = new HashMap<>();
        for (int index = 0; index < nums.length; index++) {
            if (map.get(target - nums[index]) != null) {
                indices[1] = index;
                indices[0] = map.get(target - nums[index]);
                return indices;
            }
            map.put(nums[index], index);
        }
        return indices;
    }
}

public class Solution {
    public static final int[] twoSum(
        final int[] nums, 
        final int target
    ) {
        int[] indices = new int[2];
        HashMap<Integer, Integer> map = new HashMap<>();
        for (int index = 0; index < nums.length; index++) {
            if (map.get(target - nums[index]) != null) {
                indices[1] = index;
                indices[0] = map.get(target - nums[index]);
                return indices;
            }
            map.put(nums[index], index);
        }
        return indices;
    }
}