first commit

extern/stdcxx/4.2.1/examples/tutorial/alg5.cpp

@@ -0,0 +1,199 @@
+/**************************************************************************
+ *
+ * alg5.cpp - Example programs for STL generic algorithms those 
+ *            producing scalar values.
+ *
+ * $Id: alg5.cpp 550991 2007-06-26 23:58:07Z sebor $
+ *
+ ***************************************************************************
+ *
+ * Licensed to the Apache Software  Foundation (ASF) under one or more
+ * contributor  license agreements.  See  the NOTICE  file distributed
+ * with  this  work  for  additional information  regarding  copyright
+ * ownership.   The ASF  licenses this  file to  you under  the Apache
+ * License, Version  2.0 (the  "License"); you may  not use  this file
+ * except in  compliance with the License.   You may obtain  a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the  License is distributed on an  "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY  KIND, either  express or
+ * implied.   See  the License  for  the  specific language  governing
+ * permissions and limitations under the License.
+ *
+ * Copyright 1994-2006 Rogue Wave Software.
+ * 
+ **************************************************************************/
+ 
+#include <algorithm>    // for copy
+#include <functional>   // for multiplies
+#include <iterator>     // for ostream_iterator
+#include <list>         // for list
+#include <numeric>      // for accumulate
+#include <iostream>     // for cout, endl
+   
+#include <examples.h>
+
+typedef std::ostream_iterator<int, char, std::char_traits<char> >
+        ostrm_iter_type;
+
+// Forward declarations.
+bool isVowel (char);
+void count_example ();
+void accumulate_example ();
+void inner_product_example ();
+void equal_example ();
+
+
+bool isVowel (char c) {
+    
+    switch (c)
+    {
+        case 'a': case 'A':
+        case 'e': case 'E':
+        case 'i': case 'I':
+        case 'o': case 'O':
+        case 'u': case 'U':
+            return true;
+    }
+    return false;
+}
+
+
+// Illustrate the use of the count function.
+void count_example () {
+    
+    int ecount     = 0;
+    int vowelCount = 0;
+    
+    char text[] = "Now is the time to begin";
+    
+#ifdef _RWSTD_STRICT_ANSI
+
+    ecount = std::count (text, text + sizeof text, 'e');
+    vowelCount = std::count_if (text, text + sizeof text, isVowel);
+
+#else
+
+    std::count (text, text + sizeof text, 'e', ecount);
+    std::count_if (text, text + sizeof text, isVowel, vowelCount);
+
+#endif   // _RWSTD_STRICT_ANSI
+    
+    std::cout << "There are "           << ecount
+              << " letter e's "         << std::endl
+              << "and "                 << vowelCount
+              << " vowels in the text:" << text
+              << std::endl;
+}
+
+
+// Add n to 1 to std::list.
+std::list<int, std::allocator<int> >&
+intReplicate (std::list<int, std::allocator<int> >& nums, int n) {
+
+    while (n)
+        nums.push_back (n--);
+    return nums;
+}
+
+
+// Illustrate the use of the accumulate function.
+void accumulate_example () {
+    
+    int numbers[] = { 1, 2, 3, 4, 5 };
+    int sum     = std::accumulate (numbers, numbers+5, 0);
+    int product = std::accumulate (numbers,
+                                   numbers+5, 1, std::multiplies<int> ());
+
+    std::cout << "The sum of the first five numbers is "
+              << sum
+              << std::endl;
+    std::cout << "The product of the first five numbers is "
+              << product
+              << std::endl;
+
+    // Example with different types for init.
+    std::list<int, std::allocator<int> > nums;
+    nums = std::accumulate (numbers, numbers+5, nums, intReplicate);
+
+    std::copy (nums.begin (), nums.end (), ostrm_iter_type (std::cout, " ")); 
+
+    std::cout << std::endl;
+}
+
+
+// Illustrate the use of the inner_product function.
+void inner_product_example () {
+    
+    int a[] = { 4, 3, -2 };
+    int b[] = { 7, 3, 2  };
+
+    // Example 1, simple inner product.
+    int in1 = std::inner_product (a, a+3, b, 0);
+    std::cout << "Inner product is " << in1 << std::endl;
+
+    // Example 2, using different operations.
+    bool anyequal = std::inner_product (a, a+3, b, true,
+                                        std::logical_or<bool> (),
+                                        std::equal_to<int> ());
+
+    std::cout << "any equal? " << anyequal << std::endl;  
+}
+
+
+// Illustrate the use of the equal function.
+void equal_example () {
+    
+    int a[] = { 4, 5, 3 };
+    int b[] = { 4, 3, 3 };
+    int c[] = { 4, 5, 3 };
+    
+    std::cout << "a = b is:" << std::equal (a, a+3, b) << std::endl;
+    std::cout << "a = c is:" << std::equal (a, a+3, c) << std::endl;
+    std::cout << "a pair-wise-greater_equal b is"
+              << std::equal (a, a+3, b, std::greater_equal<int> ())
+              << std::endl;
+}
+
+
+// Illustrate the use of the lexical_comparison function.
+void lexical_comparison_example () {
+
+    char wordOne[] = "everything";
+    char wordTwo[] = "everybody";
+    
+    std::cout << "compare everybody to everything "
+              << std::lexicographical_compare (wordTwo,
+                                               wordTwo + sizeof wordTwo,
+                                               wordOne,
+                                               wordOne + sizeof wordOne)
+              << std::endl;
+            
+    int a[] = { 3, 4, 5, 2 };
+    int b[] = { 3, 4, 5 };
+    int c[] = { 3, 5 };
+    
+    std::cout << "compare a to b: "
+              << std::lexicographical_compare (a, a+4, b, b+3) << std::endl;
+    std::cout << "compare a to c: "
+              << std::lexicographical_compare (a, a+4, c, c+2) << std::endl;
+}
+
+int main () {
+    
+    std::cout << "STL generic algorithms -- "\
+              << "algorithms that produce scalar results" << std::endl;
+
+    count_example ();
+    accumulate_example ();
+    inner_product_example ();
+    equal_example ();
+    lexical_comparison_example ();
+    
+    std::cout << "End of scalar algorithms test"  << std::endl;
+
+    return 0;
+}