【C++ Primer | 07】泛型算法

定制操作

---

 #include <iostream>
 #include <string>
 #include <vector>
 #include <algorithm>
 #include <numeric>
 #include <list>
 using namespace std;

 template <typename Sequence>
 inline ostream& println(Sequence const& seq)
 {
     for (auto const& elem : seq)
         cout << elem << " ";
     cout << endl;
     return cout;
 }

 inline bool is_shorter(std::string const& lhs, std::string const& rhs)
 {
     return  lhs.size() < rhs.size();
 }

 void elimdups(vector<string> &vs)
 {
     sort(vs.begin(), vs.end());
     auto new_end = unique(vs.begin(), vs.end());
     vs.erase(new_end, vs.end());
 }

 int main()
 {
     vector<", "Hi", "alan", "wang" };
     elimdups(v);
     stable_sort(v.begin(), v.end(), is_shorter);
     cout << "ex10.11 :\n";
     println(v);
     system("pause");
     ;
 }

输出结果：

Exercise 10.14：

---

 int main()
 {
     auto sum = [](int a, int b) {return a + b; };
     cout << sum(, ) << endl;
     ;
 }

Exercise 10.16

 #include <iostream>
 #include <string>
 #include <vector>
 #include <algorithm>
 using namespace std;

 void elimdups(vector<string> &vs)
 {
     sort(vs.begin(), vs.end());
     for (auto c : vs)
         cout << c << " ";
     cout << endl;

     auto new_end = unique(vs.begin(), vs.end());
     vs.erase(new_end, vs.end());
     for (auto c : vs)
         cout << c << " ";
     cout << endl;

 }

 void biggies(vector<string> &vs, size_t sz)
 {
     elimdups(vs);
     stable_sort(vs.begin(), vs.end(), [](string const& lhs, string const& rhs) {
         return lhs.size() < rhs.size(); });

     auto wc = find_if(vs.begin(), vs.end(), [sz](string const& s) {
         return s.size() >= sz; });

     for_each(wc, vs.end(), [](const string &s) {
         cout << s << " ";
     });
 }

 int main()
 {
     vector<string> v{
         ","hi~", "alan", "alan", "cp"
     };
     cout << "ex10.16: " << endl;
     biggies(v, );
     cout << endl;
     system("pause");
     ;
 }

输出结果：

Exercise 10.18、10.19

 #include <iostream>
 #include <string>
 #include <vector>
 #include <algorithm>
 using namespace std;

 // from ex 10.9
 void elimdups(vector<string> &vs)
 {
     sort(vs.begin(), vs.end());
     auto new_end = unique(vs.begin(), vs.end());
     vs.erase(new_end, vs.end());
     for (auto it = vs.cbegin(); it != vs.end(); ++it)
         cout << *it << " ";
     cout << endl;
 }

 // ex10.18
 void biggies_partition(vector<string> &vs, size_t sz)
 {
     elimdups(vs);
     auto pivot = partition(vs.begin(), vs.end(), [sz](const string &s) {
         return s.size() >= sz; }
     );

     for (auto it = vs.cbegin(); it != pivot; ++it)
         cout << *it << " ";

 }

 // ex10.19
 void biggies_stable_partition(vector<string> &vs, std::size_t sz)
 {
     elimdups(vs);

     auto pivot = stable_partition(vs.begin(), vs.end(), [sz](const string& s) {
         return s.size() >= sz; });

     for (auto it = vs.cbegin(); it != pivot; ++it)
         cout << *it << " ";
 }

 int main()
 {
     // ex10.18
     vector<string> v{
         "the", "quick", "red", "fox", "jumps", "over", "the", "slow", "red", "turtle"
     };

     cout << "ex10.18: ";
     vector<string> v1(v);
     biggies_partition(v1, );
     cout << endl;

     // ex10.19
     cout << "ex10.19: ";
     vector<std::string> v2(v);
     biggies_stable_partition(v2, );
     cout << endl;
     system("pause");
     ;
 }

输出结果：

参数绑定

Exercise 10.22：

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

 using namespace std;
 using namespace std::placeholders;

 bool isLesserThanOrEqualTo6(const string &s, string::size_type sz)
 {
     return s.size() <= sz;
 }

 int main()
 {
     vector<string> authors{ "Mooophy", "pezy", "Queequeg90", "shbling", "evan617" };
     cout << count_if(authors.cbegin(), authors.cend(), bind(isLesserThanOrEqualTo6, _1, )) << endl;
     system("pause");
     ;
 }

Exercise 10.24：

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

using namespace std;
using namespace std::placeholders;

auto check_size(string const& str, size_t sz)
{
    return str.size() < sz;
}

int main()
{
    vector<, , , , , , ,  };
    ");
    auto result = find_if(vec.begin(), vec.end(), bind(check_size, str, _1));
    if (result != vec.end())
        cout << *result << endl;
    else
        cout << "Not found" << endl;
    system("pause");
    ;
}

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

using namespace std;
using namespace std::placeholders;

auto check_size(string const& str, size_t sz)
{
    return str.size() < sz;
}

int main()
{
    vector<int> vec{ 0, 1, 2, 3, 4, 5, 6, 7 };
    string str("123456");
    auto result = find_if(vec.begin(), vec.end(), bind(check_size, str, _1));
    if (result != vec.end())
        cout << *result << endl;
    else
        cout << "Not found" << endl;
    system("pause");
    return 0;
}

　

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

using namespace std;
using namespace std::placeholders;

auto check_size(string const& str, size_t sz)
{
    return str.size() < sz;
}

int main()
{
    vector<int> vec{ 0, 1, 2, 3, 4, 5, 6, 7 };
    string str("123456");
    auto result = find_if(vec.begin(), vec.end(), bind(check_size, str, _1));
    if (result != vec.end())
        cout << *result << endl;
    else
        cout << "Not found" << endl;
    system("pause");
    return 0;
}