title: Generate random pairs of numbers, without duplicates
body: <p>I have to arrays with integers:</p>
  
  <pre><code>int[] a={1,2,3,4,5};
  int[] b={6,7};
  </code></pre>
  
  <p>I would like to generate an array, which contains pairs from the a and b arrays, in a random order, without duplicates. For example I would like to get the following result:</p>
  
  <pre><code>c={(1,6),(2,7),(4,6),...}
  </code></pre>
  
  <p>Thanks!</p>