title: C++ calculation error including pow and subtraction
body: <p>I'm working on CSES number spiral problem and I've noticed that c++ isn't calculating it right?</p>
  <pre><code>ans = pow(y, 2) - (x-1);
  </code></pre>
  <p>This is the code and I have x and y both set as 1000000000.</p>
  <pre><code>cout &lt;&lt; &quot;pow =&quot; &lt;&lt; pow(y, 2) &lt;&lt; &quot;\n&quot;;
  cout &lt;&lt; &quot;x-1 =&quot; &lt;&lt; (x - 1) &lt;&lt; &quot;\n&quot;;
  </code></pre>
  <p>I've put this right before the calculation and pow shows up correct with 1e18 and x-1 is also correct with 999999999.</p>
  <pre><code>cout &lt;&lt; 1000000000000000000 - 999999999 &lt;&lt; &quot;\n&quot;;
  </code></pre>
  <p>If I manually write it like this it works but pow(y,2) - (x-1) doesn't.
  It will give me an answer of 999999999000000000.</p>