Number of soldiers in the queue

Basic Data Structure of the queue ~

Enter a positive integer N, representing N soldiers numbered 1-N. Start to report the number. First, 1212 reports are reported to 2, and then 123123 reports to 3; then there are another 1212 reports until there are only three people whose numbers are less than or equal.

Example:

Input: 20

Output: 1 7 19

Code:

 1 #include <iostream> 2 using namespace std; 3 int que[10001] = { 0 }; 4 int main() 5 { 6     int n; 7     cin >> n; 8     int head = 1, tail = 1; 9     for (int i = 1; i <= n; i++) que[tail++] = i;10     while (1)11     {12         n = tail - head;13         if (tail - head <= 3)break;14         for (int i = 1; i <= n; i++)15         {16             if (i % 2 == 1)que[tail++] = que[head];17             head++;18         }19         n = tail - head;20         if (tail - head <= 3)break;21         for (int i = 1; i <= n; i++)22         {23             if (i % 3 != 0)que[tail++] = que[head];24             head++;25         }26     }27     for (int i = head; i < tail; i++)28     {29         cout << que[i] << " ";30     }31 }

Result:

 

Number of soldiers in the queue