title: which datastructure or stl to be used to save a pair with a value?
body: <p>I have a data like</p>
  
  <pre><code>**"London","Paris" -&gt; 10
  "New York","Japan" -&gt; 100
  "London","Japan" -&gt; 200**
  ..
  </code></pre>
  
  <p>How to save pair with value using STL? As Map only allow key and value, not extra key. </p>
  
  <p>I can save key with extra object which will hold the 2 values.</p>
  
  <pre><code> map &lt; string, Object&gt;
  </code></pre>
  
  <p>But then i have to go through an extra step of parsing the object and it will be an overhead.</p>
  
  <p>Even i can do my work using linked list. But is there any other efficient way to save it and access it? Or i am thinking in correct direction? I am new to STL.</p>