1. Two Sum

水题。

class Solution {                              public:                                       vector<int> twoSum(vector<int>& nums, int target) {            vector<int> result;                       int idx_i, idx_j;                         bool solved = false;                      for (idx_i = 0; idx_i < nums.size() - 1; idx_i++) {                if (solved) {                                 break;                                }                                         for (idx_j = idx_i+1; idx_j < nums.size(); idx_j++) {                    if (solved) {                                 break;                                }                                         if (nums[idx_i] + nums[idx_j] == target) {                        result.push_back(idx_i);                                                                                                                                                                                            result.push_back(idx_j);                        solved = true;                               break;                                }                                     }                                     }                                                                                   return result;                        }                                 };