Leetcode1 两数求和

Leetcode1 两数求和

题目描述

解题代码

public class TwoSum
{
	public static void main(String[] args)
	{
		int[] nums={11,15,2,7};		
		int target=9;
		System.out.println(Arrays.toString(twoSum(nums, target)));

	}
	public static int[] twoSum(int[] nums,int target) {
		if (nums==null||nums.length<2)
		{
			return new int[] {-1,-1};
		}
		int[] res=new int[] {-1,-1};
		HashMap<Integer, Integer>map=new HashMap<>();
		for (int i = 0; i < nums.length; i++)
		{
			//containsKey方法——判断是否包含指定的键名
			if (map.containsKey(target-nums[i]))
			{
				res[0]=map.get(target-nums[i]);
				res[1]=i;
				break;
			}
			map.put(nums[i], i);
		}
		return res;
	}
}