C++primer 9.3.1节练习

练习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 }

练习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 }

练习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         else
23             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 }

练习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 }

练习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         else
27             ++iter;
28     }
29     for (auto c : iv)
30         cout << c << endl;
31     system("pause");
32     return 0;
33 }

一个是该循环是个死循环，iter永远不会不等于mid，第二点很重要，自己在做题时有遗漏，向一个vector、string、deque插入元素会使所有指向容器的迭代器、引用和指针失效。