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 <H2>lexicographical_compare()</H2>
 <P><B>Library:</B>&nbsp;&nbsp;<A HREF="2-9.html">Algorithms</A></P>

 <PRE><HR><B><I>Function</I></B><HR></PRE>

 <UL>
 <LI><A HREF="#sec1">Local Index</A></LI>
 <LI><A HREF="#sec2">Summary</A></LI>
 <LI><A HREF="#sec3">Synopsis</A></LI>
 <LI><A HREF="#sec4">Description</A></LI>
 <LI><A HREF="#sec5">Complexity</A></LI>
 <LI><A HREF="#sec6">Example</A></LI>
 <LI><A HREF="#sec7">Standards Conformance</A></LI>
 </UL>
 <A NAME="sec1"><H3>Local Index</H3></A>
 No Entries
 <A NAME="sec2"><H3>Summary</H3></A>
 <P>Algorithm that returns <SAMP>true</SAMP> if one sequence compares lexicographically less than another, <SAMP>false</SAMP> otherwise</P>
 <A NAME="sec3"><H3>Synopsis</H3></A>

 <PRE>#include &lt;algorithm&gt;

 namespace std {
   template &lt;class InputIterator1, class InputIterator2&gt;
   bool
   lexicographical_compare(InputIterator1 start1,
                           InputIterator1 finish1,
                           InputIterator2 start2,
                           InputIterator2 finish2);

   template &lt;class InputIterator1, class InputIterator2,
             class Compare&gt;
    bool
    lexicographical_compare(InputIterator1 start1,
                            InputIterator1 finish1,
                            InputIterator2 start2,
                            InputIterator2 finish2,
                            Compare comp);
 }
 </PRE>
 <A NAME="sec4"><H3>Description</H3></A>
 <P>The <SAMP>lexicographical_compare()</SAMP> functions compare each element in the range <SAMP>[start1, finish1)</SAMP> to the corresponding element in the range <SAMP>[start2, finish2)</SAMP> using iterators <SAMP>i</SAMP> and <SAMP>j</SAMP>. </P>
 <P>The first version of the algorithm uses <SAMP>operator&lt;()</SAMP> as the default comparison operator. It immediately returns <SAMP>true</SAMP> if it encounters any pair in which <SAMP>*i</SAMP> is less than <SAMP>*j</SAMP>, and immediately returns <SAMP>false</SAMP> if <SAMP>*j</SAMP> is less than <SAMP>*i</SAMP>. If the algorithm reaches the end of the first sequence before reaching the end of the second sequence, it also returns <SAMP>true</SAMP>. </P>
 <P>The second version of the function takes an argument <SAMP>comp</SAMP> that defines a comparison function that is used in place of the default <SAMP>operator&lt;()</SAMP>.</P>
 <P>The <SAMP>lexicographical_compare()</SAMP> functions can be used with all the data types included in the standard library.</P>
 <A NAME="sec5"><H3>Complexity</H3></A>
 <P><SAMP>lexicographical_compare()</SAMP> performs at most <SAMP>min((finish1 - start1), (finish2  -  start2))</SAMP> applications of the comparison function.</P>
 <A NAME="sec6"><H3>Example</H3></A>

 <UL><PRE>//
 //  lex_comp.cpp
 //

 #include &lt;algorithm&gt;
 #include &lt;functional&gt;
 #include &lt;iostream&gt;
 #include &lt;vector&gt;

 int main()
 {
     typedef std::vector&lt;int, std::allocator&lt;int&gt; &gt; Vector;

     const Vector::value_type d1[] = { 1, 3, 5, 32, 64 };
     const Vector::value_type d2[] = { 1, 3, 2, 43, 56 };

     // Create vectors.
     Vector v1 (d1 + 0, d1 + sizeof d1 / sizeof *d1);
     Vector v2 (d2 + 0, d2 + sizeof d1 / sizeof *d2);

     // Is v1 less than v2 (I think not).
     bool b1 = std::lexicographical_compare (v1.begin (),
                       v1.end (), v2.begin (), v2.end ());

     // Is v2 less than v1 (yup, sure is).
     bool b2 = std::lexicographical_compare(v2.begin (),
                       v2.end (), v1.begin (), v1.end (),
                       std::less&lt;int&gt;());

     std::cout &lt;&lt; std::boolalpha &lt;&lt; b1
               &lt;&lt; " " &lt;&lt; b2 &lt;&lt; std::endl;

     return 0;
 }


 Program Output:
 </PRE></UL>
 <UL><PRE>false true

 </PRE></UL>
 <A NAME="sec7"><H3>Standards Conformance</H3></A>
 <P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 25.3.8</I></P>

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	<H2>lexicographical_compare()</H2>
	<P><B>Library:</B>  <A HREF="2-9.html">Algorithms</A></P>

	<PRE><HR><B><I>Function</I></B><HR></PRE>

	<UL>
	<LI><A HREF="#sec1">Local Index</A></LI>
	<LI><A HREF="#sec2">Summary</A></LI>
	<LI><A HREF="#sec3">Synopsis</A></LI>
	<LI><A HREF="#sec4">Description</A></LI>
	<LI><A HREF="#sec5">Complexity</A></LI>
	<LI><A HREF="#sec6">Example</A></LI>
	<LI><A HREF="#sec7">Standards Conformance</A></LI>
	</UL>
	<A NAME="sec1"><H3>Local Index</H3></A>
	No Entries
	<A NAME="sec2"><H3>Summary</H3></A>
	<P>Algorithm that returns <SAMP>true</SAMP> if one sequence compares lexicographically less than another, <SAMP>false</SAMP> otherwise</P>
	<A NAME="sec3"><H3>Synopsis</H3></A>

	<PRE>#include <algorithm>

	namespace std {
	template <class InputIterator1, class InputIterator2>
	bool
	lexicographical_compare(InputIterator1 start1,
	InputIterator1 finish1,
	InputIterator2 start2,
	InputIterator2 finish2);

	template <class InputIterator1, class InputIterator2,
	class Compare>
	bool
	lexicographical_compare(InputIterator1 start1,
	InputIterator1 finish1,
	InputIterator2 start2,
	InputIterator2 finish2,
	Compare comp);
	}
	</PRE>
	<A NAME="sec4"><H3>Description</H3></A>
	<P>The <SAMP>lexicographical_compare()</SAMP> functions compare each element in the range <SAMP>[start1, finish1)</SAMP> to the corresponding element in the range <SAMP>[start2, finish2)</SAMP> using iterators <SAMP>i</SAMP> and <SAMP>j</SAMP>. </P>
	<P>The first version of the algorithm uses <SAMP>operator<()</SAMP> as the default comparison operator. It immediately returns <SAMP>true</SAMP> if it encounters any pair in which <SAMP>i</SAMP> is less than <SAMP>j</SAMP>, and immediately returns <SAMP>false</SAMP> if <SAMP>j</SAMP> is less than <SAMP>i</SAMP>. If the algorithm reaches the end of the first sequence before reaching the end of the second sequence, it also returns <SAMP>true</SAMP>. </P>
	<P>The second version of the function takes an argument <SAMP>comp</SAMP> that defines a comparison function that is used in place of the default <SAMP>operator<()</SAMP>.</P>
	<P>The <SAMP>lexicographical_compare()</SAMP> functions can be used with all the data types included in the standard library.</P>
	<A NAME="sec5"><H3>Complexity</H3></A>
	<P><SAMP>lexicographical_compare()</SAMP> performs at most <SAMP>min((finish1 - start1), (finish2 - start2))</SAMP> applications of the comparison function.</P>
	<A NAME="sec6"><H3>Example</H3></A>

	<UL><PRE>//
	// lex_comp.cpp
	//

	#include <algorithm>
	#include <functional>
	#include <iostream>
	#include <vector>

	int main()
	{
	typedef std::vector<int, std::allocator<int> > Vector;

	const Vector::value_type d1[] = { 1, 3, 5, 32, 64 };
	const Vector::value_type d2[] = { 1, 3, 2, 43, 56 };

	// Create vectors.
	Vector v1 (d1 + 0, d1 + sizeof d1 / sizeof *d1);
	Vector v2 (d2 + 0, d2 + sizeof d1 / sizeof *d2);

	// Is v1 less than v2 (I think not).
	bool b1 = std::lexicographical_compare (v1.begin (),
	v1.end (), v2.begin (), v2.end ());

	// Is v2 less than v1 (yup, sure is).
	bool b2 = std::lexicographical_compare(v2.begin (),
	v2.end (), v1.begin (), v1.end (),
	std::less<int>());

	std::cout << std::boolalpha << b1
	<< " " << b2 << std::endl;

	return 0;
	}


	Program Output:
	</PRE></UL>
	<UL><PRE>false true

	</PRE></UL>
	<A NAME="sec7"><H3>Standards Conformance</H3></A>
	<P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 25.3.8</I></P>

	<BR>
	<HR>
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