Read the elements between the beginning and end of the List repeatedly.

You need to solve the following problem recently:

Read all the content in a list and output it (for example, to the screen). The first and last rows are output only once, and all the rows in the middle are output twice. For example, a list contains the following content:

1

2

3

4

Output it to the screen. The expected result is as follows:

1

2

2

3

3

4

I implemented it using the following program:

 1 #include <iostream>
 2 #include <list>
 3 
 4 using namespace std;
 5 
 6 int main()
 7 {
 8     list<int> intList;
 9     list<int>::iterator intIterator;
10 
11     for (int i = 0; i < 4; i++)
12     {
13         intList.push_back(i + 1);
14     }
15     for (intIterator = intList.begin(); intIterator != intList.end(); intIterator++)
16     {
17         if (intIterator == intList.begin())
18         {
19             cout << *intIterator << "\t";
20         } else {
21             cout << *intIterator << endl;
22             intIterator++;
23             if (intIterator != intList.end())
24             {
25                 intIterator--;
26                 cout << *intIterator << "\t";
27             } else {
28                 break;
29             }
30         }
31     }
32 
33     return 0;
34 }