labs/lab05/code/inlab/BinarySearchTree.cpp.html

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<pre><b><span style="color:#000080">#include</span></b> <span style="color:#FF0000">"BinaryNode.h"</span>
<b><span style="color:#000080">#include</span></b> <span style="color:#FF0000">"BinarySearchTree.h"</span>
<b><span style="color:#000080">#include</span></b> <span style="color:#FF0000">&lt;iostream&gt;</span>
<b><span style="color:#000080">#include</span></b> <span style="color:#FF0000">&lt;string&gt;</span>
<b><span style="color:#0000FF">using</span></b> <b><span style="color:#0000FF">namespace</span></b> std<span style="color:#990000">;</span>

BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">BinarySearchTree</span></b><span style="color:#990000">()</span> <span style="color:#FF0000">{</span>
    root <span style="color:#990000">=</span> NULL<span style="color:#990000">;</span>
<span style="color:#FF0000">}</span>

BinarySearchTree<span style="color:#990000">::~</span><b><span style="color:#000000">BinarySearchTree</span></b><span style="color:#990000">()</span> <span style="color:#FF0000">{</span>
    <b><span style="color:#0000FF">delete</span></b> root<span style="color:#990000">;</span>
    root <span style="color:#990000">=</span> NULL<span style="color:#990000">;</span>
<span style="color:#FF0000">}</span>

<i><span style="color:#9A1900">// insert finds a position for x in the tree and places it there.</span></i>
<span style="color:#009900">void</span> BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">insert</span></b><span style="color:#990000">(</span><b><span style="color:#0000FF">const</span></b> string<span style="color:#990000">&amp;</span> x<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
    <i><span style="color:#9A1900">// YOUR IMPLEMENTATION GOES HERE</span></i>
<span style="color:#FF0000">}</span>

<i><span style="color:#9A1900">// remove finds x's position in the tree and removes it.</span></i>
<span style="color:#009900">void</span> BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">remove</span></b><span style="color:#990000">(</span><b><span style="color:#0000FF">const</span></b> string<span style="color:#990000">&amp;</span> x<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
    root <span style="color:#990000">=</span> <b><span style="color:#000000">remove</span></b><span style="color:#990000">(</span>root<span style="color:#990000">,</span> x<span style="color:#990000">);</span>
<span style="color:#FF0000">}</span>

<i><span style="color:#9A1900">// private helper for remove to allow recursion over different nodes. returns</span></i>
<i><span style="color:#9A1900">// a BinaryNode* that is assigned to the original node.</span></i>
BinaryNode<span style="color:#990000">*</span> BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">remove</span></b><span style="color:#990000">(</span>BinaryNode<span style="color:#990000">*&amp;</span> n<span style="color:#990000">,</span> <b><span style="color:#0000FF">const</span></b> string<span style="color:#990000">&amp;</span> x<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
    <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>n <span style="color:#990000">==</span> NULL<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
        <b><span style="color:#0000FF">return</span></b> NULL<span style="color:#990000">;</span>
    <span style="color:#FF0000">}</span>

    <i><span style="color:#9A1900">// first look for x</span></i>
    <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>x <span style="color:#990000">==</span> n<span style="color:#990000">-&gt;</span>value<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
        <i><span style="color:#9A1900">// found</span></i>
        <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>n<span style="color:#990000">-&gt;</span>left <span style="color:#990000">==</span> NULL <span style="color:#990000">&amp;&amp;</span> n<span style="color:#990000">-&gt;</span>right <span style="color:#990000">==</span> NULL<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
            <i><span style="color:#9A1900">// no children</span></i>
            <i><span style="color:#9A1900">// just delete it :)</span></i>
            <b><span style="color:#0000FF">delete</span></b> n<span style="color:#990000">;</span>
            n <span style="color:#990000">=</span> NULL<span style="color:#990000">;</span>
            <b><span style="color:#0000FF">return</span></b> NULL<span style="color:#990000">;</span>
        <span style="color:#FF0000">}</span> <b><span style="color:#0000FF">else</span></b> <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>n<span style="color:#990000">-&gt;</span>left <span style="color:#990000">==</span> NULL<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
            <i><span style="color:#9A1900">// single child (right)</span></i>
            <i><span style="color:#9A1900">// remove current node and return right child node for parent</span></i>
            BinaryNode<span style="color:#990000">*</span> temp <span style="color:#990000">=</span> n<span style="color:#990000">-&gt;</span>right<span style="color:#990000">;</span>
            n<span style="color:#990000">-&gt;</span>right <span style="color:#990000">=</span> NULL<span style="color:#990000">;</span>
            <b><span style="color:#0000FF">delete</span></b> n<span style="color:#990000">;</span>
            n <span style="color:#990000">=</span> NULL<span style="color:#990000">;</span>
            <b><span style="color:#0000FF">return</span></b> temp<span style="color:#990000">;</span>
        <span style="color:#FF0000">}</span> <b><span style="color:#0000FF">else</span></b> <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>n<span style="color:#990000">-&gt;</span>right <span style="color:#990000">==</span> NULL<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
            <i><span style="color:#9A1900">// single child (left)</span></i>
            <i><span style="color:#9A1900">// remove current node and return left child node for parent</span></i>
            BinaryNode<span style="color:#990000">*</span> temp <span style="color:#990000">=</span> n<span style="color:#990000">-&gt;</span>left<span style="color:#990000">;</span>
            n<span style="color:#990000">-&gt;</span>left <span style="color:#990000">=</span> NULL<span style="color:#990000">;</span>
            <b><span style="color:#0000FF">delete</span></b> n<span style="color:#990000">;</span>
            n <span style="color:#990000">=</span> NULL<span style="color:#990000">;</span>
            <b><span style="color:#0000FF">return</span></b> temp<span style="color:#990000">;</span>
        <span style="color:#FF0000">}</span> <b><span style="color:#0000FF">else</span></b> <span style="color:#FF0000">{</span>
            <i><span style="color:#9A1900">// two children</span></i>
            <i><span style="color:#9A1900">// replace current node with right child node's minimum, then remove that node</span></i>
            <span style="color:#008080">string</span> value <span style="color:#990000">=</span> <b><span style="color:#000000">min</span></b><span style="color:#990000">(</span>n<span style="color:#990000">-&gt;</span>right<span style="color:#990000">);</span>
            n<span style="color:#990000">-&gt;</span>value <span style="color:#990000">=</span> value<span style="color:#990000">;</span>
            n<span style="color:#990000">-&gt;</span>right <span style="color:#990000">=</span> <b><span style="color:#000000">remove</span></b><span style="color:#990000">(</span>n<span style="color:#990000">-&gt;</span>right<span style="color:#990000">,</span> value<span style="color:#990000">);</span>
        <span style="color:#FF0000">}</span>
    <span style="color:#FF0000">}</span> <b><span style="color:#0000FF">else</span></b> <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>x <span style="color:#990000">&lt;</span> n<span style="color:#990000">-&gt;</span>value<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
        n<span style="color:#990000">-&gt;</span>left <span style="color:#990000">=</span> <b><span style="color:#000000">remove</span></b><span style="color:#990000">(</span>n<span style="color:#990000">-&gt;</span>left<span style="color:#990000">,</span> x<span style="color:#990000">);</span>
    <span style="color:#FF0000">}</span> <b><span style="color:#0000FF">else</span></b> <span style="color:#FF0000">{</span>
        n<span style="color:#990000">-&gt;</span>right <span style="color:#990000">=</span> <b><span style="color:#000000">remove</span></b><span style="color:#990000">(</span>n<span style="color:#990000">-&gt;</span>right<span style="color:#990000">,</span> x<span style="color:#990000">);</span>
    <span style="color:#FF0000">}</span>
    <b><span style="color:#0000FF">return</span></b> n<span style="color:#990000">;</span>
<span style="color:#FF0000">}</span>

<i><span style="color:#9A1900">// pathTo finds x in the tree and returns a string representing the path it</span></i>
<i><span style="color:#9A1900">// took to get there.</span></i>
<span style="color:#008080">string</span> BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">pathTo</span></b><span style="color:#990000">(</span><b><span style="color:#0000FF">const</span></b> string<span style="color:#990000">&amp;</span> x<span style="color:#990000">)</span> <b><span style="color:#0000FF">const</span></b> <span style="color:#FF0000">{</span>
    <i><span style="color:#9A1900">// YOUR IMPLEMENTATION GOES HERE</span></i>
<span style="color:#FF0000">}</span>

<i><span style="color:#9A1900">// find determines whether or not x exists in the tree.</span></i>
<span style="color:#009900">bool</span> BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">find</span></b><span style="color:#990000">(</span><b><span style="color:#0000FF">const</span></b> string<span style="color:#990000">&amp;</span> x<span style="color:#990000">)</span> <b><span style="color:#0000FF">const</span></b> <span style="color:#FF0000">{</span>
    <i><span style="color:#9A1900">// YOUR IMPLEMENTATION GOES HERE</span></i>
<span style="color:#FF0000">}</span>

<i><span style="color:#9A1900">// numNodes returns the total number of nodes in the tree.</span></i>
<span style="color:#009900">int</span> BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">numNodes</span></b><span style="color:#990000">()</span> <b><span style="color:#0000FF">const</span></b> <span style="color:#FF0000">{</span>
    <i><span style="color:#9A1900">// YOUR IMPLEMENTATION GOES HERE</span></i>
<span style="color:#FF0000">}</span>

<i><span style="color:#9A1900">// min finds the string with the smallest value in a subtree.</span></i>
<span style="color:#008080">string</span> BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">min</span></b><span style="color:#990000">(</span>BinaryNode<span style="color:#990000">*</span> node<span style="color:#990000">)</span> <b><span style="color:#0000FF">const</span></b> <span style="color:#FF0000">{</span>
    <i><span style="color:#9A1900">// go to bottom-left node</span></i>
    <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>node<span style="color:#990000">-&gt;</span>left <span style="color:#990000">==</span> NULL<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
        <b><span style="color:#0000FF">return</span></b> node<span style="color:#990000">-&gt;</span>value<span style="color:#990000">;</span>
    <span style="color:#FF0000">}</span>
    <b><span style="color:#0000FF">return</span></b> <b><span style="color:#000000">min</span></b><span style="color:#990000">(</span>node<span style="color:#990000">-&gt;</span>left<span style="color:#990000">);</span>
<span style="color:#FF0000">}</span>

<i><span style="color:#9A1900">// Helper function to print branches of the binary tree</span></i>
<i><span style="color:#9A1900">// You do not need to know how this function works.</span></i>
<span style="color:#009900">void</span> <b><span style="color:#000000">showTrunks</span></b><span style="color:#990000">(</span>Trunk<span style="color:#990000">*</span> p<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
    <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>p <span style="color:#990000">==</span> NULL<span style="color:#990000">)</span> <b><span style="color:#0000FF">return</span></b><span style="color:#990000">;</span>
    <b><span style="color:#000000">showTrunks</span></b><span style="color:#990000">(</span>p<span style="color:#990000">-&gt;</span>prev<span style="color:#990000">);</span>
    cout <span style="color:#990000">&lt;&lt;</span> p<span style="color:#990000">-&gt;</span>str<span style="color:#990000">;</span>
<span style="color:#FF0000">}</span>

<span style="color:#009900">void</span> BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">printTree</span></b><span style="color:#990000">()</span> <span style="color:#FF0000">{</span>
    <b><span style="color:#000000">printTree</span></b><span style="color:#990000">(</span>root<span style="color:#990000">,</span> NULL<span style="color:#990000">,</span> <b><span style="color:#0000FF">false</span></b><span style="color:#990000">);</span>
<span style="color:#FF0000">}</span>

<i><span style="color:#9A1900">// Recursive function to print binary tree</span></i>
<i><span style="color:#9A1900">// It uses inorder traversal</span></i>
<span style="color:#009900">void</span> BinarySearchTree<span style="color:#990000">::</span><b><span style="color:#000000">printTree</span></b><span style="color:#990000">(</span>BinaryNode<span style="color:#990000">*</span> root<span style="color:#990000">,</span> Trunk<span style="color:#990000">*</span> prev<span style="color:#990000">,</span> <span style="color:#009900">bool</span> isRight<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
    <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>root <span style="color:#990000">==</span> NULL<span style="color:#990000">)</span> <b><span style="color:#0000FF">return</span></b><span style="color:#990000">;</span>

    <span style="color:#008080">string</span> prev_str <span style="color:#990000">=</span> <span style="color:#FF0000">"    "</span><span style="color:#990000">;</span>
    Trunk<span style="color:#990000">*</span> trunk <span style="color:#990000">=</span> <b><span style="color:#0000FF">new</span></b> <b><span style="color:#000000">Trunk</span></b><span style="color:#990000">(</span>prev<span style="color:#990000">,</span> prev_str<span style="color:#990000">);</span>

    <b><span style="color:#000000">printTree</span></b><span style="color:#990000">(</span>root<span style="color:#990000">-&gt;</span>right<span style="color:#990000">,</span> trunk<span style="color:#990000">,</span> <b><span style="color:#0000FF">true</span></b><span style="color:#990000">);</span>

    <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(!</span>prev<span style="color:#990000">)</span>
        trunk<span style="color:#990000">-&gt;</span>str <span style="color:#990000">=</span> <span style="color:#FF0000">"---"</span><span style="color:#990000">;</span>
    <b><span style="color:#0000FF">else</span></b> <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>isRight<span style="color:#990000">)</span> <span style="color:#FF0000">{</span>
        trunk<span style="color:#990000">-&gt;</span>str <span style="color:#990000">=</span> <span style="color:#FF0000">".---"</span><span style="color:#990000">;</span>
        prev_str <span style="color:#990000">=</span> <span style="color:#FF0000">"   |"</span><span style="color:#990000">;</span>
    <span style="color:#FF0000">}</span> <b><span style="color:#0000FF">else</span></b> <span style="color:#FF0000">{</span>
        trunk<span style="color:#990000">-&gt;</span>str <span style="color:#990000">=</span> <span style="color:#FF0000">"`---"</span><span style="color:#990000">;</span>
        prev<span style="color:#990000">-&gt;</span>str <span style="color:#990000">=</span> prev_str<span style="color:#990000">;</span>
    <span style="color:#FF0000">}</span>

    <b><span style="color:#000000">showTrunks</span></b><span style="color:#990000">(</span>trunk<span style="color:#990000">);</span>
    cout <span style="color:#990000">&lt;&lt;</span> root<span style="color:#990000">-&gt;</span>value <span style="color:#990000">&lt;&lt;</span> endl<span style="color:#990000">;</span>

    <b><span style="color:#0000FF">if</span></b> <span style="color:#990000">(</span>prev<span style="color:#990000">)</span> prev<span style="color:#990000">-&gt;</span>str <span style="color:#990000">=</span> prev_str<span style="color:#990000">;</span>
    trunk<span style="color:#990000">-&gt;</span>str <span style="color:#990000">=</span> <span style="color:#FF0000">"   |"</span><span style="color:#990000">;</span>

    <b><span style="color:#000000">printTree</span></b><span style="color:#990000">(</span>root<span style="color:#990000">-&gt;</span>left<span style="color:#990000">,</span> trunk<span style="color:#990000">,</span> <b><span style="color:#0000FF">false</span></b><span style="color:#990000">);</span>

    <b><span style="color:#0000FF">delete</span></b> trunk<span style="color:#990000">;</span>
<span style="color:#FF0000">}</span>
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