C++primer 9.3.1節練習

標籤：const   指標   main   while   insert   auto   sys   color   log   

練習9.18

 1 #include <iostream> 2 #include <vector> 3 #include <list> 4 #include <deque> 5 #include <string> 6 #include <iterator> 7  8 using namespace std; 9 10 int main()11 {12     deque<string> de;13     string word;14     while (cin >> word)15     {16         de.push_back(word);17     }18     for (auto it = de.begin(); it != de.end(); ++it)19         cout << *it << endl;20     system("pause");21     return 0;22 }

練習9.19

 1 #include <iostream> 2 #include <vector> 3 #include <list> 4 #include <deque> 5 #include <string> 6 #include <iterator> 7  8 using namespace std; 9 10 int main()11 {12     list<string> de;13     string word;14     while (cin >> word)15     {16         de.push_back(word);17     }18     for (auto it = de.begin(); it != de.end(); ++it)19         cout << *it << endl;20     system("pause");21     return 0;22 }

練習9.20

 1 #include <iostream> 2 #include <vector> 3 #include <list> 4 #include <deque> 5 #include <string> 6 #include <iterator> 7  8 using namespace std; 9 10 void print(const deque<int> de);11 12 int main()13 {14     list<int> num;15     num.insert(num.begin(), { 1,2,3,4,5,6,7,8,9,10 });16     deque<int> num1;17     deque<int> num2;18     for (auto it = num.begin(); it != num.end(); ++it)19     {20         if ((*it) % 2 == 0)21             num1.push_back(*it);22         else23             num2.push_back(*it);24     }25     print(num1);26     cout << endl;27     print(num2);28     system("pause");29     return 0;30 }31 32 void print(const deque<int> de)33 {34     for (auto c : de)35         cout << c << endl;36 }

練習9.21

 1 #include <iostream> 2 #include <vector> 3 #include <list> 4 #include <deque> 5 #include <string> 6 #include <iterator> 7  8 using namespace std; 9 10 11 int main()12 {13     vector<string> lst;14     string word;15     auto iter = lst.end();16     while (cin >> word)17     {18         iter = lst.insert(iter, word);19     }20     for (auto c : lst)21         cout << c << endl;22     system("pause");23     return 0;24 }

練習9.22

 1 #include <iostream> 2 #include <vector> 3 #include <list> 4 #include <deque> 5 #include <string> 6 #include <iterator> 7  8 using namespace std; 9 10 11 int main()12 {13     int some_val = 1;14     vector<int> iv{ 1,2,3,4,5,6,7,8,9,10 };15     auto i = iv.size();16     vector<int>::iterator iter = iv.begin(),17         mid = iv.begin() + iv.size() / 2;18     while (iter != mid)19     {20         if (*iter == some_val)21         {22             iter = iv.insert(iter, 2 * some_val);23             iter = iter + 2;24             mid = iv.begin() + i / 2;25         }26         else27             ++iter;28     }29     for (auto c : iv)30         cout << c << endl;31     system("pause");32     return 0;33 }

一個是該迴圈是個死迴圈，iter永遠不會不等於mid，第二點很重要，自己在做題時有遺漏，向一個vector、string、deque插入元素會使所有指向容器的迭代器、引用和指標失效。

C++primer 9.3.1節練習