OpenSoure_Repos/TheAlgorithms-C
1
0
Fork 0
mirror of https://github.moeyy.xyz/https://github.com/TheAlgorithms/C.git synced 2023-10-11 15:56:24 +08:00
Code Issues Packages Projects Releases Wiki Activity
351f6e3554
TheAlgorithms-C/d2/d93/problem__8_2sol2_8c.html
github-actions 351f6e3554 Documentation for 103361de54
2023-01-20 04:13:50 +00:00

289 lines
22 KiB
HTML
Raw Blame History

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=11"/>
<meta name="generator" content="Doxygen 1.9.6"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>Algorithms_in_C: project_euler/problem_8/sol2.c File Reference</title>
<link href="../../tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="../../jquery.js"></script>
<script type="text/javascript" src="../../dynsections.js"></script>
<link href="../../navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="../../resize.js"></script>
<script type="text/javascript" src="../../navtreedata.js"></script>
<script type="text/javascript" src="../../navtree.js"></script>
<link href="../../search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="../../search/searchdata.js"></script>
<script type="text/javascript" src="../../search/search.js"></script>
<script type="text/x-mathjax-config">
MathJax.Hub.Config({
extensions: ["tex2jax.js", "TeX/AMSmath.js", "TeX/AMSsymbols.js"],
jax: ["input/TeX","output/HTML-CSS"],
});
</script>
<script type="text/javascript" async="async" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.7/MathJax.js?config=TeX-MML-AM_CHTML/MathJax.js"></script>
<link href="../../doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr id="projectrow">
<td id="projectalign">
<div id="projectname">Algorithms_in_C<span id="projectnumber">&#160;1.0.0</span>
</div>
<div id="projectbrief">Set of algorithms implemented in C.</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.9.6 -->
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
var searchBox = new SearchBox("searchBox", "../../search/",'.html');
/* @license-end */
</script>
<script type="text/javascript" src="../../menudata.js"></script>
<script type="text/javascript" src="../../menu.js"></script>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
$(function() {
initMenu('../../',true,false,'search.php','Search');
$(document).ready(function() { init_search(); });
});
/* @license-end */
</script>
<div id="main-nav"></div>
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
<div id="nav-tree">
<div id="nav-tree-contents">
<div id="nav-sync" class="sync"></div>
</div>
</div>
<div id="splitbar" style="-moz-user-select:none;"
class="ui-resizable-handle">
</div>
</div>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
$(document).ready(function(){initNavTree('d2/d93/problem__8_2sol2_8c.html','../../'); initResizable(); });
/* @license-end */
</script>
<div id="doc-content">
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
</div>
<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<div id="MSearchResults">
<div class="SRPage">
<div id="SRIndex">
<div id="SRResults"></div>
<div class="SRStatus" id="Loading">Loading...</div>
<div class="SRStatus" id="Searching">Searching...</div>
<div class="SRStatus" id="NoMatches">No Matches</div>
</div>
</div>
</div>
</div>
<div class="header">
<div class="summary">
<a href="#func-members">Functions</a> </div>
<div class="headertitle"><div class="title">sol2.c File Reference</div></div>
</div><!--header-->
<div class="contents">
<p><a href="https://projecteuler.net/problem=8" target="_blank">Problem 8</a> solution
<a href="#details">More...</a></p>
<div class="textblock"><code>#include &lt;stdio.h&gt;</code><br />
<code>#include &lt;stdlib.h&gt;</code><br />
<code>#include &lt;string.h&gt;</code><br />
</div><div class="textblock"><div class="dynheader">
Include dependency graph for sol2.c:</div>
<div class="dyncontent">
<div class="center"><iframe scrolling="no" frameborder="0" src="../../d0/d3d/problem__8_2sol2_8c__incl.svg" width="251" height="124"><p><b>This browser is not able to show SVG: try Firefox, Chrome, Safari, or Opera instead.</b></p></iframe>
</div>
</div>
</div><table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a id="func-members" name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:a0ddf1224851353fc92bfbff6f499fa97"><td class="memItemLeft" align="right" valign="top">int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="../../d2/d93/problem__8_2sol2_8c.html#a0ddf1224851353fc92bfbff6f499fa97">main</a> (int argc, char *argv[])</td></tr>
<tr class="memdesc:a0ddf1224851353fc92bfbff6f499fa97"><td class="mdescLeft">&#160;</td><td class="mdescRight">Main function. <br /></td></tr>
<tr class="separator:a0ddf1224851353fc92bfbff6f499fa97"><td class="memSeparator" colspan="2">&#160;</td></tr>
</table>
<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2>
<div class="textblock"><p><a href="https://projecteuler.net/problem=8" target="_blank">Problem 8</a> solution </p>
<dl class="section author"><dt>Author</dt><dd><a href="https://github.com/kvedala" target="_blank">Krishna Vedala</a> </dd></dl>
</div><h2 class="groupheader">Function Documentation</h2>
<a id="a0ddf1224851353fc92bfbff6f499fa97" name="a0ddf1224851353fc92bfbff6f499fa97"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a0ddf1224851353fc92bfbff6f499fa97">&#9670;&#160;</a></span>main()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">int main </td>
<td>(</td>
<td class="paramtype">int&#160;</td>
<td class="paramname"><em>argc</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">char *&#160;</td>
<td class="paramname"><em>argv</em>[]&#160;</td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<p>Main function. </p>
<div class="fragment"><div class="line"><span class="lineno"> 12</span>{</div>
<div class="line"><span class="lineno"> 13</span> <span class="keywordtype">int</span> position = 0, num_bad_chars = 0;</div>
<div class="line"><span class="lineno"> 14</span> <span class="keywordtype">int</span> num_digits = 4;</div>
<div class="line"><span class="lineno"> 15</span> <span class="keywordtype">char</span> ch;</div>
<div class="line"><span class="lineno"> 16</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> num, num_prev;</div>
<div class="line"><span class="lineno"> 17</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *<a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a> = NULL;</div>
<div class="line"><span class="lineno"> 18</span> <span class="keywordtype">long</span> <span class="keywordtype">long</span> <span class="keywordtype">int</span> prod = 1, max_prod = 0;</div>
<div class="line"><span class="lineno"> 19</span> </div>
<div class="line"><span class="lineno"> 20</span> <span class="comment">/* if second command-line argument is given,</span></div>
<div class="line"><span class="lineno"> 21</span><span class="comment"> * use it as the number of digits to compute</span></div>
<div class="line"><span class="lineno"> 22</span><span class="comment"> * successive product for</span></div>
<div class="line"><span class="lineno"> 23</span><span class="comment"> */</span></div>
<div class="line"><span class="lineno"> 24</span> <span class="keywordflow">if</span> (argc == 2)</div>
<div class="line"><span class="lineno"> 25</span> num_digits = atoi(argv[1]);</div>
<div class="line"><span class="lineno"> 26</span> </div>
<div class="line"><span class="lineno"> 27</span> <span class="comment">/* allocate memory to store past values */</span></div>
<div class="line"><span class="lineno"> 28</span> <a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a> = <a class="code hl_define" href="../../d2/ddd/malloc__dbg_8h.html#afdddaa949a93c1ef559a638e98f9c21b">calloc</a>(num_digits, <span class="keyword">sizeof</span>(<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>));</div>
<div class="line"><span class="lineno"> 29</span> <span class="keywordflow">if</span> (!<a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a>)</div>
<div class="line"><span class="lineno"> 30</span> {</div>
<div class="line"><span class="lineno"> 31</span> perror(<span class="stringliteral">&quot;Unable to allocate memory for buffer&quot;</span>);</div>
<div class="line"><span class="lineno"> 32</span> <span class="keywordflow">return</span> -1;</div>
<div class="line"><span class="lineno"> 33</span> }</div>
<div class="line"><span class="lineno"> 34</span> </div>
<div class="line"><span class="lineno"> 35</span> <span class="comment">/* open file to read digits from */</span></div>
<div class="line"><span class="lineno"> 36</span> FILE *fp = fopen(<span class="stringliteral">&quot;digits.txt&quot;</span>, <span class="stringliteral">&quot;rt&quot;</span>);</div>
<div class="line"><span class="lineno"> 37</span> <span class="keywordflow">if</span> (!fp)</div>
<div class="line"><span class="lineno"> 38</span> {</div>
<div class="line"><span class="lineno"> 39</span> perror(<span class="stringliteral">&quot;Unable to open file&quot;</span>);</div>
<div class="line"><span class="lineno"> 40</span> <a class="code hl_define" href="../../d2/ddd/malloc__dbg_8h.html#a9cc854374299a1dd933bf62029761768">free</a>(<a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a>); <span class="comment">/* free allocated memory */</span></div>
<div class="line"><span class="lineno"> 41</span> <span class="keywordflow">return</span> -1;</div>
<div class="line"><span class="lineno"> 42</span> }</div>
<div class="line"><span class="lineno"> 43</span> </div>
<div class="line"><span class="lineno"> 44</span> <span class="comment">/* loop through all digits in the file */</span></div>
<div class="line"><span class="lineno"> 45</span> <span class="keywordflow">do</span></div>
<div class="line"><span class="lineno"> 46</span> {</div>
<div class="line"><span class="lineno"> 47</span> <span class="comment">/* get character from file */</span></div>
<div class="line"><span class="lineno"> 48</span> ch = getc(fp);</div>
<div class="line"><span class="lineno"> 49</span> </div>
<div class="line"><span class="lineno"> 50</span> <span class="comment">/* the ASCII codes of digits is between 0x30 and 0x39.</span></div>
<div class="line"><span class="lineno"> 51</span><span class="comment"> * any character not in this range implies an invalid character</span></div>
<div class="line"><span class="lineno"> 52</span><span class="comment"> */</span></div>
<div class="line"><span class="lineno"> 53</span> <span class="keywordflow">if</span> (ch &lt; 0x30 || ch &gt; 0x39)</div>
<div class="line"><span class="lineno"> 54</span> {</div>
<div class="line"><span class="lineno"> 55</span> num_bad_chars++; <span class="comment">/* this is used to get the bad characters in the</span></div>
<div class="line"><span class="lineno"> 56</span><span class="comment"> sequence of 13 characters */</span></div>
<div class="line"><span class="lineno"> 57</span> <span class="keywordflow">continue</span>;</div>
<div class="line"><span class="lineno"> 58</span> }</div>
<div class="line"><span class="lineno"> 59</span> <span class="keywordflow">else</span> <span class="keywordflow">if</span> (num_bad_chars &gt; 0)</div>
<div class="line"><span class="lineno"> 60</span> num_bad_chars--;</div>
<div class="line"><span class="lineno"> 61</span> </div>
<div class="line"><span class="lineno"> 62</span> num = ch - 0x30; <span class="comment">/* convert character digit to number */</span></div>
<div class="line"><span class="lineno"> 63</span> num_prev = <a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a>[0]; <span class="comment">/* previous n^th digit */</span></div>
<div class="line"><span class="lineno"> 64</span> </div>
<div class="line"><span class="lineno"> 65</span> <span class="comment">/* left shift the buffer -</span></div>
<div class="line"><span class="lineno"> 66</span><span class="comment"> * using a for loop or a faster memory move</span></div>
<div class="line"><span class="lineno"> 67</span><span class="comment"> */</span></div>
<div class="line"><span class="lineno"> 68</span> memmove(<a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a>, <a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a> + 1, num_digits - 1);</div>
<div class="line"><span class="lineno"> 69</span> <span class="comment">/*</span></div>
<div class="line"><span class="lineno"> 70</span><span class="comment"> for (int i = 1; i &lt; num_digits; i++)</span></div>
<div class="line"><span class="lineno"> 71</span><span class="comment"> buffer[i-1] = buffer[i];</span></div>
<div class="line"><span class="lineno"> 72</span><span class="comment"> */</span></div>
<div class="line"><span class="lineno"> 73</span> </div>
<div class="line"><span class="lineno"> 74</span> <a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a>[num_digits - 1] = num; <span class="comment">/* save the latest number in buffer */</span></div>
<div class="line"><span class="lineno"> 75</span> </div>
<div class="line"><span class="lineno"> 76</span> <span class="keywordflow">if</span> (num_prev != 0)</div>
<div class="line"><span class="lineno"> 77</span> {</div>
<div class="line"><span class="lineno"> 78</span> <span class="comment">/* since product is accumulated, the new product can be obtained by</span></div>
<div class="line"><span class="lineno"> 79</span><span class="comment"> * simply multiplying the new digit and dividing with the oldest</span></div>
<div class="line"><span class="lineno"> 80</span><span class="comment"> * digit</span></div>
<div class="line"><span class="lineno"> 81</span><span class="comment"> */</span></div>
<div class="line"><span class="lineno"> 82</span> prod /= num_prev; <span class="comment">/* divide first to avoid over-flows */</span></div>
<div class="line"><span class="lineno"> 83</span> prod *= num;</div>
<div class="line"><span class="lineno"> 84</span> }</div>
<div class="line"><span class="lineno"> 85</span> <span class="keywordflow">else</span></div>
<div class="line"><span class="lineno"> 86</span> {</div>
<div class="line"><span class="lineno"> 87</span> prod = 1;</div>
<div class="line"><span class="lineno"> 88</span> <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; num_digits; i++)</div>
<div class="line"><span class="lineno"> 89</span> {</div>
<div class="line"><span class="lineno"> 90</span> <span class="keywordflow">if</span> (<a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a>[i] == 0)</div>
<div class="line"><span class="lineno"> 91</span> {</div>
<div class="line"><span class="lineno"> 92</span> prod = 0;</div>
<div class="line"><span class="lineno"> 93</span> <span class="keywordflow">break</span>; <span class="comment">/* break innermost for-loop */</span></div>
<div class="line"><span class="lineno"> 94</span> }</div>
<div class="line"><span class="lineno"> 95</span> prod *= <a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a>[i];</div>
<div class="line"><span class="lineno"> 96</span> }</div>
<div class="line"><span class="lineno"> 97</span> }</div>
<div class="line"><span class="lineno"> 98</span> </div>
<div class="line"><span class="lineno"> 99</span> <span class="comment">/* check if a new maxima was found */</span></div>
<div class="line"><span class="lineno"> 100</span> <span class="keywordflow">if</span> (prod &gt; max_prod)</div>
<div class="line"><span class="lineno"> 101</span> {</div>
<div class="line"><span class="lineno"> 102</span> max_prod = prod;</div>
<div class="line"><span class="lineno"> 103</span> position = ftell(fp) - num_bad_chars - num_digits - 1;</div>
<div class="line"><span class="lineno"> 104</span> }</div>
<div class="line"><span class="lineno"> 105</span> } <span class="keywordflow">while</span> (!feof(fp)); <span class="comment">/* loop till end of file is reached */</span></div>
<div class="line"><span class="lineno"> 106</span> </div>
<div class="line"><span class="lineno"> 107</span> printf(<span class="stringliteral">&quot;Maximum product: %lld\t Location: %d^th position\n\t&quot;</span>, max_prod,</div>
<div class="line"><span class="lineno"> 108</span> position);</div>
<div class="line"><span class="lineno"> 109</span> fseek(fp, position,</div>
<div class="line"><span class="lineno"> 110</span> SEEK_SET); <span class="comment">/* move cursor to identified position in file */</span></div>
<div class="line"><span class="lineno"> 111</span> <span class="comment">/* loop through all digits */</span></div>
<div class="line"><span class="lineno"> 112</span> <span class="keywordflow">for</span> (; num_digits &gt; 0; num_digits--)</div>
<div class="line"><span class="lineno"> 113</span> {</div>
<div class="line"><span class="lineno"> 114</span> <span class="keywordtype">char</span> ch = getc(fp); <span class="comment">/* get character */</span></div>
<div class="line"><span class="lineno"> 115</span> <span class="comment">/* skip invalid character */</span></div>
<div class="line"><span class="lineno"> 116</span> <span class="keywordflow">if</span> (ch &lt; 0x30 || ch &gt; 0x39)</div>
<div class="line"><span class="lineno"> 117</span> <span class="keywordflow">continue</span>;</div>
<div class="line"><span class="lineno"> 118</span> <span class="keywordflow">if</span> (num_digits &gt; 1)</div>
<div class="line"><span class="lineno"> 119</span> printf(<span class="stringliteral">&quot;%c x &quot;</span>, ch);</div>
<div class="line"><span class="lineno"> 120</span> <span class="keywordflow">else</span></div>
<div class="line"><span class="lineno"> 121</span> printf(<span class="stringliteral">&quot;%c = %lld\n&quot;</span>, ch, max_prod);</div>
<div class="line"><span class="lineno"> 122</span> }</div>
<div class="line"><span class="lineno"> 123</span> </div>
<div class="line"><span class="lineno"> 124</span> fclose(fp); <span class="comment">/* close file */</span></div>
<div class="line"><span class="lineno"> 125</span> <a class="code hl_define" href="../../d2/ddd/malloc__dbg_8h.html#a9cc854374299a1dd933bf62029761768">free</a>(<a class="code hl_struct" href="../../dd/da2/structbuffer.html">buffer</a>); <span class="comment">/* free allocated memory */</span></div>
<div class="line"><span class="lineno"> 126</span> </div>
<div class="line"><span class="lineno"> 127</span> <span class="keywordflow">return</span> 0;</div>
<div class="line"><span class="lineno"> 128</span>}</div>
<div class="ttc" id="amalloc__dbg_8h_html_a9cc854374299a1dd933bf62029761768"><div class="ttname"><a href="../../d2/ddd/malloc__dbg_8h.html#a9cc854374299a1dd933bf62029761768">free</a></div><div class="ttdeci">#define free(ptr)</div><div class="ttdoc">This macro replace the standard free function with free_dbg.</div><div class="ttdef"><b>Definition:</b> malloc_dbg.h:26</div></div>
<div class="ttc" id="amalloc__dbg_8h_html_afdddaa949a93c1ef559a638e98f9c21b"><div class="ttname"><a href="../../d2/ddd/malloc__dbg_8h.html#afdddaa949a93c1ef559a638e98f9c21b">calloc</a></div><div class="ttdeci">#define calloc(elemCount, elemSize)</div><div class="ttdoc">This macro replace the standard calloc function with calloc_dbg.</div><div class="ttdef"><b>Definition:</b> malloc_dbg.h:22</div></div>
<div class="ttc" id="astructbuffer_html"><div class="ttname"><a href="../../dd/da2/structbuffer.html">buffer</a></div><div class="ttdoc">struct used to store character in certain times</div><div class="ttdef"><b>Definition:</b> min_printf.h:31</div></div>
</div><!-- fragment -->
</div>
</div>
</div><!-- contents -->
</div><!-- doc-content -->
<!-- start footer part -->
<div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
<ul>
<li class="navelem"><a class="el" href="../../dir_b3d331eabd4234f247030c297aaf021c.html">project_euler</a></li><li class="navelem"><a class="el" href="../../dir_4a15c8553efb9e59e3f1091cc0d3a27d.html">problem_8</a></li><li class="navelem"><a class="el" href="../../d2/d93/problem__8_2sol2_8c.html">sol2.c</a></li>
<li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="../../doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.6 </li>
</ul>
</div>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink