题解 | #两数之和#

利用两数互补和哈希查找的原理

class Solution {
public:
    /**
     * 
     * @param numbers int整型vector 
     * @param target int整型 
     * @return int整型vector
     */
    vector<int> twoSum(vector<int>& numbers, int target) {
      std::vector<int> res;
      std::unordered_map<int, int> hash;
      
      for (int i = 0; i < numbers.size(); ++i) {
        int tmp = target - numbers[i];
        
        //  找不到
        if (hash.find(tmp) == hash.end()) {
          hash.insert({numbers[i], i});
        } else {
          res.push_back(hash[tmp] + 1);
          res.push_back(i + 1);
          break;
        }
      }
      
      return res;
    }
};