LeetCode 1 两数之和

class Solution {
    public int[] twoSum(int[] nums, int target) {
       Map<Integer, Integer> map = new HashMap<>();
       for(int i=0; i<nums.length;++i)
            map.put(nums[i],i);
       for(int i=0; i<nums.length;++i)
       {
       if(map.containsKey(target - nums[i]) && map.get(target - nums[i]) != i)
       {
           return new int []{i, map.get(target - nums[i])};
       }
       }
       throw new IllegalArgumentException("No two sum solution");
    }
}