数据结构：双链表

题目描述

输入样例

10
R 7
D 1
L 3
IL 2 10
D 3
IL 2 7
L 8
R 9
IL 4 7
IR 2 2

输出样例

8 7 7 3 2 9

参考代码

#include <iostream>using namespace std;const int N = 100010;int m;
int idx, e[N], l[N], r[N];void init()
{r[0] = 1;l[1] = 0;idx = 2;
}void insert(int k, int x)
{e[idx] = x;l[idx] = k; r[idx] = r[k];l[r[k]] = idx; r[k] = idx;idx++;
}void remove(int k)
{l[r[k]] = l[k];r[l[k]] = r[k];
}int main()
{init();cin >> m;while (m--){int k, x;string op;cin >> op;if (op == "L"){   cin >> x;insert(0, x);}else if (op == "R"){cin >> x;insert(l[1], x);}else if (op == "D"){   cin >> k;remove(k + 1);}else if (op == "IL"){cin >> k >> x;insert(l[k + 1], x);}else{cin >> k >> x;insert(k + 1, x);}}for (int i = r[0]; i != 1; i = r[i]) cout << e[i] << ' ';cout << endl;return 0;
}