卡片游戏

由于只对表头操作，可以用数组来模拟队列

#include <iostream>
using namespace std;

int const maxn = 1000;


int main() {
    int t;
    cin>>t;
    while (t--) {
        int n; cin>>n;
        int a[maxn];
        for (int i=1;i<=n;i++) a[i] = i;
        int p1 = 1,p2 = n;
        while (p1+1<=p2) {
            cout<<a[p1]<<" ";
            p1++;
            p2++; a[p2] = a[p1];
            p1++;
        }
         cout<<a[p2]<<endl;

    }
}

链表比较数组而言就要烦杂许多了，要根据具体情况具体选用链表，
如一个节点的，单向的还是双向的，节点在前面的还是在后面的。循环过程也要具体去分析以避免越界。

#include <iostream>
using namespace std;

struct ListNode {
    int val;
    ListNode* left;
    ListNode* right;
    ListNode(int a=0):val(a),left(NULL),right(NULL){}
};

typedef ListNode* _tr;

_tr fir,rear;


int main() {
    int t;
    cin>>t;
    while (t--) {
        int n;
        cin>>n;
        fir= new ListNode(0);
        rear = new ListNode(0);
        _tr tmp = fir; 
        for (int i=1;i<=n;i++) {
            _tr nu = new ListNode(i);
            tmp->right = nu;
            nu-> left = tmp;
            tmp=tmp->right;
        }
        tmp->right = rear;
        rear->left = tmp;

        while(fir->right->val!=0&&fir->right->right->val!=0) {
            _tr k = fir->right;
            _tr kk = fir->right->right;
            fir->right = kk->right;
            kk->right->left = fir;
            cout<<k->val<<' '; 
            delete k;
            rear->left->right = kk;
            kk->left = rear->left;
            rear->left = kk;
            kk->right = rear;

        }
        cout<<fir->right->val<<endl; 
    }

}