Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>I suspect that you want something like this:</p> <pre><code>size_t displayAscend(nodePtr p, int count) { size_t additional_count = 0; if (p-&gt;left != NULL) additional_count += displayAscend(p-&gt;left, count + additional_count); cout &lt;&lt; count + additional_count &lt;&lt; ". " &lt;&lt; p-&gt;acctNum &lt;&lt; endl; additional_count++; if (p-&gt;right != NULL) additional_count += displayAscend(p-&gt;right, count + additional_count); return additional_count; } </code></pre> <p>You can use <code>int</code> in place of <code>size_t</code> if you prefer.</p> <p>The reason is that each recursive call must return a count to its caller, for otherwise the caller cannot tell how many the recursive call has counted. The outermost caller, of course, can just discard the count if uninterested.</p> <p>Passing by reference is another way to do it, as another answer observes, though not my preferred way. (I personally prefer to implement <em>that</em> strategy with explicit pointers.)</p> <p>You ask whether making <code>count</code> a global variable would work. The answer is that, yes, it would <em>work</em> for the restricted purpose of your limited exercise, but it would represent abysmal programming practice. After all, what if you had several trees, each with its own count?</p> <p><em>Update:</em> Thanks to @JerryCoffin for pointing out the former error in my code. I have fixed it above. What is more, I have tested it with the following:</p> <pre><code>#include &lt;vector&gt; #include &lt;iostream&gt; using std::cout; using std::endl; struct node { node *left; node *right; int acctNum; }; typedef node *nodePtr; size_t displayAscend(nodePtr p, int count) { size_t additional_count = 0; if (p-&gt;left != NULL) additional_count += displayAscend(p-&gt;left, count + additional_count); cout &lt;&lt; count + additional_count &lt;&lt; ". " &lt;&lt; p-&gt;acctNum &lt;&lt; endl; additional_count++; if (p-&gt;right != NULL) additional_count += displayAscend(p-&gt;right, count + additional_count); return additional_count; } int main() { node head; node n1; node n2; node n11; node n21; node n22; head.left = &amp;n1; head.right = &amp;n2; n1 .left = &amp;n11; n1 .right = 0; n2 .left = &amp;n21; n2 .right = &amp;n22; n11 .left = 0; n11 .right = 0; n21 .left = 0; n21 .right = 0; n22 .left = 0; n22 .right = 0; n11 .acctNum = 100; n1 .acctNum = 202; head.acctNum = 300; n21 .acctNum = 400; n2 .acctNum = 500; n22 .acctNum = 600; displayAscend(&amp;head, 0); } </code></pre> <p>The output is</p> <pre><code>0. 100 1. 202 2. 300 3. 400 4. 500 5. 600 </code></pre> <p>So, it works.</p>
    singulars
    1. This table or related slice is empty.
    1. POBinary Search Tree displaying nodes recursively
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USthb
    1. USthb
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. CO@JerryCoffin: Good point, my error. Let me work on that now.
      singulars
      1. PO
      1. USthb
    2. CO@JerryCoffin: The tree recursion is now fixed per your advice, and properly tested, this time, too. Thanks.
      singulars
      1. PO
      1. USthb
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload