Problem description

Given an array of integers, return indices of the two numbers such that they add up to a specific target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.

Input

Given nums = [2, 7, 11, 15], target = 9,
Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].

Code

class Solution {
    public int[] twoSum(int[] nums, int target) {
        
        int len = nums.length;
        for(int i = 0; i < len; i++) {
            for(int j = i + 1; j < len; j++) {
                if(nums[i] + nums[j] == target) {
                    return new int[]{i, j};
                }
            }
        }
        return null;
    }
}

Analysis

过于简单不分析。