题目如下：

Given an array of integers, find two numbers such that they add up to a specific target number.

The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note that your returned answers (both index1 and index2) are not zero-based.

You may assume that each input would have exactly one solution.

Input: numbers={2, 7, 11, 15}, target=9
Output: index1=1, index2=2

题中有个注意点：返回相加等于目标值地两个数的索引值加1，案例中，2和7相加等于9；但2在数组中的索引是0，7在数组中的索引为1，要求输出却是1和2，所以我们应该把索引值加1.其它的双重遍历，没什么好说的

代码如下：

class Solution {
public:
    vector<int> twoSum(vector<int> &numbers, int target) {
      int Len = numbers.size();
      vector<int> result;
      for(int i = 0;i < Len;i++)
      {
          //numbers[i]为第一个相加值
          if(numbers[i] <= target)
          {
              for(int j = i+1;j < Len;j++)
              {
                  int temp = target - numbers[i];
                  //numbers[j]为第二个相加值
                  if(numbers[j] == temp)
                  {         
                      //索引值加1       
                      result.push_back(i+1);
                      result.push_back(j+1);
                      return result;
                  }
                  
              }
          }
      }
    }
};