title: why the output in negative (using bitwise-not)
body: <pre><code>void main()
  {
          unsigned int a = 10;
          a = ~a;
          printf("%d\n", a);
  }
  </code></pre>
  
  <p>the output is <code>-11</code></p>
  
  <p>10 = 1010</p>
  
  <p>~10 = 0101</p>
  
  <p>why the output is negative?</p>