1.

class Solution {public:    vector
     
       twoSum(vector
      
        &numbers, int target) {        // IMPORTANT: Please reset any member data you declared, as        // the same Solution instance will be reused for each test case.       map
       
         mp;       int len = numbers.size();              for( int i=0; i < len; ++i )       {           mp[ numbers[ i ] ] = i + 1;       }              vector
        
          result;              for( int i = 0; i < len; ++i )       {           map
         
          ::iterator it = mp.find( target - numbers[i] );                      if( it != mp.end() )           {              result.push_back(it->second);              result.push_back(i+1);              sort(result.begin(),result.end());              break;           }       }       return result;       };};
         
        
       
      
     

　　

使用multimap实现；比较笨的方法（map中的键值对是按键排序粗放的）。

class Solution {public:    vector
     
       twoSum(vector
      
        &numbers, int target) {        // IMPORTANT: Please reset any member data you declared, as        // the same Solution instance will be reused for each test case.       multimap
       
         tmp;              for( int i = 1; i <= numbers.size(); ++i )       {           tmp.insert(pair
        
         (numbers[i-1],i));       }              multimap
         
          ::iterator index1= tmp.begin();       multimap
          
           ::iterator index2 = --tmp.end(); while( index1 != index2 ) { int sum = index1->first + index2->first; if( sum > target ) --index2; else if( sum < target ) ++index1; else break; } vector
           
             result; if(index1->second > index2->second) { int tmp = index1->second ; index1->second =index2->second ; index2->second=tmp; } result.push_back(index1->second); result.push_back(index2->second); return result; }};