Weitere Beispiele 21.4.2022

20220421/hash-1.cpp

+// C++ program to demonstrate various function of unordered_set
+#include <bits/stdc++.h>
+using namespace std;
+ 
+int main()
+{
+    // declaring set for storing string data-type
+    unordered_set <string> stringSet ;
+ 
+    // inserting various string, same string will be stored
+    // once in set
+ 
+    stringSet.insert("code") ;
+    stringSet.insert("in") ;
+    stringSet.insert("c++") ;
+    stringSet.insert("is") ;
+    stringSet.insert("fast") ;
+ 
+    string key = "slow" ;
+ 
+    //  find returns end iterator if key is not found,
+    //  else it returns iterator to that key
+ 
+    if (stringSet.find(key) == stringSet.end())
+        cout << key << " not found" << endl << endl ;
+    else
+        cout << "Found " << key << endl << endl ;
+ 
+    key = "c++";
+    if (stringSet.find(key) == stringSet.end())
+        cout << key << " not found\n" ;
+    else
+        cout << "Found " << key << endl ;
+ 
+    // now iterating over whole set and printing its
+    // content
+    cout << "\nAll elements : ";
+    unordered_set<string> :: iterator itr;
+    for (itr = stringSet.begin(); itr != stringSet.end(); itr++)
+        cout << (*itr) << endl;
+}

20220421/sets-24.cpp

@@ -13,11 +13,11 @@ bool less (int a, int b)
 
 int main ()
 {
-  fwd = 0;
   std::set <int, decltype (less)*> prime ({ 2, 3, 7, 11, 13 }, less);
   for (auto p : prime)
     std::cout << p << " ";
   std::cout << std::endl;
+  fwd = 0;
   prime.insert (5);
   for (auto p : prime)
     std::cout << p << " ";

20220421/sets-25.cpp

+#include <iostream>
+#include <set>
+#include <functional>
+
+bool less (int fwd, int a, int b)
+{
+  if (fwd)
+    return a < b;
+  else
+    return a > b;
+}
+
+int main ()
+{
+  int fwd = 1;
+  auto less2 = std::bind (less, fwd, std::placeholders::_1, std::placeholders::_2);
+  std::set <int, decltype (less2)*> prime ({ 2, 3, 7, 11, 13 }, &less2);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-26.cpp

+#include <iostream>
+#include <set>
+#include <functional>
+
+bool less (int fwd, int a, int b)
+{
+  if (fwd)
+    return a < b;
+  else
+    return a > b;
+}
+
+int main ()
+{
+  int fwd = 1;
+  auto less2 = std::bind (less, fwd, std::placeholders::_1, std::placeholders::_2);
+  std::cout << less2 (2, 4) << std::endl;
+  fwd = 0;
+  std::cout << less2 (2, 4) << std::endl;
+  return 0;
+}

20220421/sets-27.cpp

+#include <iostream>
+#include <set>
+#include <functional>
+
+bool less (int *fwd, int a, int b)
+{
+  if (*fwd)
+    return a < b;
+  else
+    return a > b;
+}
+
+int main ()
+{
+  int fwd = 1;
+  auto less2 = std::bind (less, &fwd, std::placeholders::_1, std::placeholders::_2);
+  std::cout << less2 (2, 4) << std::endl;
+  fwd = 0;
+  std::cout << less2 (2, 4) << std::endl;
+  return 0;
+}

20220421/sets-28.cpp

+#include <iostream>
+#include <set>
+#include <functional>
+
+bool less (int fwd, int a, int b)
+{
+  if (fwd)
+    return a < b;
+  else
+    return a > b;
+}
+
+int main ()
+{
+  int fwd = 1;
+  auto less2 = std::bind (less, fwd, std::placeholders::_1, std::placeholders::_2);
+  std::set <int, std::function <bool (int, int)>> prime ({ 2, 3, 7, 11, 13 }, less2);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-29.cpp

+#include <iostream>
+#include <set>
+#include <functional>
+#include <typeinfo>
+
+bool less (int fwd, int a, int b)
+{
+  if (fwd)
+    return a < b;
+  else
+    return a > b;
+}
+
+int main ()
+{
+  int fwd = 1;
+  auto less2 = std::bind (less, fwd, std::placeholders::_1, std::placeholders::_2);
+  std::cout << typeid (less2).name () << std::endl;
+  std::set <int, std::function <bool (int, int)>> prime ({ 2, 3, 7, 11, 13 }, less2);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-30.cpp

+#include <iostream>
+#include <set>
+#include <functional>
+
+bool less (int *fwd, int a, int b)
+{
+  if (*fwd)
+    return a < b;
+  else
+    return a > b;
+}
+
+int main ()
+{
+  int fwd = 1;
+  auto less2 = std::bind (less, &fwd, std::placeholders::_1, std::placeholders::_2);
+  std::set <int, std::function <bool (int, int)>> prime ({ 2, 3, 7, 11, 13 }, less2);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-31.cpp

+#include <iostream>
+#include <set>
+#include <functional>
+
+bool less (int &fwd, int a, int b)
+{
+  if (fwd)
+    return a < b;
+  else
+    return a > b;
+}
+
+int main ()
+{
+  int fwd = 1;
+  auto less2 = std::bind (less, fwd, std::placeholders::_1, std::placeholders::_2);
+  std::set <int, std::function <bool (int, int)>> prime ({ 2, 3, 7, 11, 13 }, less2);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-32.cpp

+#include <iostream>
+#include <set>
+#include <functional>
+
+bool less (int &fwd, int a, int b)
+{
+  if (fwd)
+    return a < b;
+  else
+    return a > b;
+}
+
+int main ()
+{
+  int fwd = 1;
+  auto less2 = std::bind (less, std::reference_wrapper <int> (fwd),
+                          std::placeholders::_1, std::placeholders::_2);
+  std::set <int, std::function <bool (int, int)>> prime ({ 2, 3, 7, 11, 13 }, less2);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-33.cpp

+#include <iostream>
+#include <set>
+#include <functional>
+
+bool less (int &fwd, int a, int b)
+{
+  if (fwd)
+    return a < b;
+  else
+    return a > b;
+}
+
+int main ()
+{
+  int fwd = 1;
+  auto less2 = std::bind (less, std::ref (fwd),
+                          std::placeholders::_1, std::placeholders::_2);
+  std::set <int, std::function <bool (int, int)>> prime ({ 2, 3, 7, 11, 13 }, less2);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-34.pas

+program Sets;
+
+procedure Sort (a, b: Integer; function less (a, b: Integer): Boolean);
+begin
+  if less (a, b) then
+    WriteLn (a, ' < ', b)
+  else
+    WriteLn (a, ' > ', b)
+end;
+
+procedure DoSomething;
+
+  function less (a, b: Integer): Boolean;
+  begin
+    if a < b then
+      less := true
+    else
+      less := false
+  end;
+
+begin
+  Sort (2, 4, less)
+end;
+
+begin
+  DoSomething
+end.

20220421/sets-35.pas

+program Sets;
+
+procedure Sort (a, b: Integer; function less (a, b: Integer): Boolean);
+begin
+  if less (a, b) then
+    WriteLn (a, ' < ', b)
+  else
+    WriteLn (a, ' > ', b)
+end;
+
+procedure DoSomething;
+
+  function less (a, b: Integer): Boolean;
+  begin
+    less := a < b
+  end;
+
+begin
+  Sort (2, 4, less)
+end;
+
+begin
+  DoSomething
+end.

20220421/sets-36.pas

+program Sets;
+
+procedure Sort (a, b: Integer; function less (a, b: Integer): Boolean);
+begin
+  if less (a, b) then
+    WriteLn (a, ' < ', b)
+  else
+    WriteLn (a, ' > ', b)
+end;
+
+procedure DoSomething;
+
+var
+  fwd: Boolean = true;
+
+  function less (a, b: Integer): Boolean;
+  begin
+    if fwd then
+      less := a < b
+    else
+      less := a > b
+  end;
+
+begin
+  Sort (2, 4, less);
+  fwd := false;
+  Sort (2, 4, less)
+end;
+
+begin
+  DoSomething
+end.

20220421/sets-37.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [&] (int a, int b)
+  {
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-38.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [=] (int a, int b)
+  {
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}