LeetCode 1. 两数之和

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++){
                if(nums[i] + nums[j] == target){
                    int[] arr = new int[]{i,j};
                    return arr;
                }
        
            }
        }
        return null;
    }
}