第14周 项目1 - 验证算法（1）

/*
* Copyright (c).2014, 烟台大学计算机学院
* All rights reserved.
*文件名称:cpp1.cpp
*作    者:董子宾
*完成日期:2015年 11月 30日
*版 本 号:v1.0
*
*问题描述：线性表的折半查找
*输入描述：无
*程序输出：测试结果
*/

问题及代码：

用有序表{12,18,24,35,47,50,62,83,90,115,134}作为测试序列，分别对查找90、47、100进行测试。 

<code class="hljs cpp has-numbering"><span class="hljs-preprocessor">#include <stdio.h></span>
<span class="hljs-preprocessor">#define MAXL 100</span>
<span class="hljs-keyword">typedef</span> <span class="hljs-keyword">int</span> KeyType;
<span class="hljs-keyword">typedef</span> <span class="hljs-keyword">char</span> InfoType[<span class="hljs-number">10</span>];
<span class="hljs-keyword">typedef</span> <span class="hljs-keyword">struct</span>
{
KeyType key; <span class="hljs-comment">//KeyType为关键字的数据类型</span>
InfoType data; <span class="hljs-comment">//其他数据</span>
} NodeType;
<span class="hljs-keyword">typedef</span> NodeType SeqList[MAXL]; <span class="hljs-comment">//顺序表类型</span>

<span class="hljs-keyword">int</span> BinSearch(SeqList R,<span class="hljs-keyword">int</span> n,KeyType k)
{
<span class="hljs-keyword">int</span> low=<span class="hljs-number">0</span>,high=n-<span class="hljs-number">1</span>,mid;
<span class="hljs-keyword">while</span> (low<=high)
{
mid=(low+high)/<span class="hljs-number">2</span>;
<span class="hljs-keyword">if</span> (R[mid].key==k) <span class="hljs-comment">//查找成功返回</span>
<span class="hljs-keyword">return</span> mid+<span class="hljs-number">1</span>;
<span class="hljs-keyword">if</span> (R[mid].key>k) <span class="hljs-comment">//继续在R[low..mid-1]中查找</span>
high=mid-<span class="hljs-number">1</span>;
<span class="hljs-keyword">else</span>
low=mid+<span class="hljs-number">1</span>; <span class="hljs-comment">//继续在R[mid+1..high]中查找</span>
}
<span class="hljs-keyword">return</span> <span class="hljs-number">0</span>;
}

<span class="hljs-keyword">int</span> main()
{
<span class="hljs-keyword">int</span> i,n=<span class="hljs-number">10</span>;
<span class="hljs-keyword">int</span> result;
SeqList R;
KeyType a[]= {<span class="hljs-number">1</span>,<span class="hljs-number">3</span>,<span class="hljs-number">9</span>,<span class="hljs-number">12</span>,<span class="hljs-number">32</span>,<span class="hljs-number">41</span>,<span class="hljs-number">45</span>,<span class="hljs-number">62</span>,<span class="hljs-number">75</span>,<span class="hljs-number">77</span>},x=<span class="hljs-number">75</span>;
<span class="hljs-keyword">for</span> (i=<span class="hljs-number">0</span>; i<n; i++)
R[i].key=a[i];
result = BinSearch(R,n,x);
<span class="hljs-keyword">if</span>(result><span class="hljs-number">0</span>)
<span class="hljs-built_in">printf</span>(<span class="hljs-string">"序列中第 %d 个是 %d\n"</span>,result, x);
<span class="hljs-keyword">else</span>
<span class="hljs-built_in">printf</span>(<span class="hljs-string">"木有找到！\n"</span>);
<span class="hljs-keyword">return</span> <span class="hljs-number">0</span>;
}</code><ul style="FILTER: ; ZOOM: 1" class="pre-numbering"><li></li></ul>运行结果：