LeetCode刷题：1.Two Sum

1. Two Sum

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.

Example:

Given nums = [2, 7, 11, 15], target = 9,

Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].

解题思路：

对数组进行遍历，将符合条件的数组元素返回；
另有高效率遍历哈希表法，待研究。

解答：

//暴力法：遍历整个数组，耗时较长（72ms）
class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) 
    {
        vector<int> result;
        int size = nums.size();
        for (int i = 0; i < size; i++)
        {
            int complement = target - nums[i];
            for (int j = i + 1; j < size; j++)
            {
                if (nums[j] == complement)
                {
                    result.push_back(i);
                    result.push_back(j);
                    return result;
                }    
            }
        }
        return result;
    }
};