【模板】文艺平衡树（Splay）区间翻转 BZOJ 3223-CFANZ编程社区

您需要写一种数据结构（可参考题目标题），来维护一个有序数列，其中需要提供以下操作：翻转一个区间，例如原有序序列是5 4 3 2 1，翻转区间是[2,4]的话，结果是5 2 3 4 1

N,M<=100000

Sample Output4 3 2 1 5 Hint

Input

第一行为n,m n表示初始序列有n个数，这个序列依次是(1,2……n-1,n) m表示翻转操作次数
接下来m行每行两个数[l,r] 数据保证 1<=l<=r<=n

Output

输出一行n个数字，表示原始序列经过m次变换后的结果

Sample Input5 3 1 3 1 3 1 4

Splay Tree ，和上道题一样，我们的kth 返回的序列的第k个数；然后中序遍历即可得到我们翻转后的序列；

#include
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#include
//#pragma GCC optimize(2)
//#include
//#pragma GCC optimize("O3")
using namespace std;
#define maxn 100005
#define inf 0x3f3f3f3f
#define INF 9999999999
#define rdint(x) scanf("%d",&x)
#define rdllt(x) scanf("%lld",&x)
#define rdult(x) scanf("%lu",&x)
#define rdlf(x) scanf("%lf",&x)
#define rdstr(x) scanf("%s",x)
typedef long long  ll;
typedef unsigned long long ull;
typedef unsigned int U;
#define ms(x) memset((x),0,sizeof(x))
const long long int mod = 1e9 + 7;
#define Mod 1000000000
#define sq(x) (x)*(x)
#define eps 1e-3
typedef pair pii;
#define pi acos(-1.0)
//const int N = 1005;
#define REP(i,n) for(int i=0;i<(n);i++)

inline ll rd() {
    ll x = 0;
    char c = getchar();
    bool f = false;
    while (!isdigit(c)) {
        if (c == '-') f = true;
        c = getchar();
    }
    while (isdigit(c)) {
        x = (x << 1) + (x << 3) + (c ^ 48);
        c = getchar();
    }
    return f ? -x : x;
}

ll gcd(ll a, ll b) {
    return b == 0 ? a : gcd(b, a%b);
}
ll sqr(ll x) { return x * x; }

/*ll ans;
ll exgcd(ll a, ll b, ll &x, ll &y) {
    if (!b) {
        x = 1; y = 0; return a;
    }
    ans = exgcd(b, a%b, x, y);
    ll t = x; x = y; y = t - a / b * y;
    return ans;
}
*/



ll qpow(ll a, ll b, ll c) {
    ll ans = 1;
    a = a % c;
    while (b) {
        if (b % 2)ans = ans * a%c;
        b /= 2; a = a * a%c;
    }
    return ans;
}

struct splay {
    int fa, ch[2], size;
    int lazy, rev, maxx, value;
}Sp[maxn];

int n, m, root, a[maxn];
void pushup(int rt) {
    Sp[rt].size = Sp[Sp[rt].ch[0]].size + Sp[Sp[rt].ch[1]].size + 1;
    Sp[rt].maxx = max(Sp[rt].value, max(Sp[Sp[rt].ch[0]].maxx, Sp[Sp[rt].ch[1]].maxx));
}

void pushdown(int rt) {
    if (Sp[rt].lazy) {
        if (Sp[rt].ch[0]) {
            Sp[Sp[rt].ch[0]].lazy += Sp[rt].lazy;
            Sp[Sp[rt].ch[0]].maxx += Sp[rt].lazy;
            Sp[Sp[rt].ch[0]].value += Sp[rt].lazy;
        }
        if (Sp[rt].ch[1]) {
            Sp[Sp[rt].ch[1]].lazy += Sp[rt].lazy;
            Sp[Sp[rt].ch[1]].maxx += Sp[rt].lazy;
            Sp[Sp[rt].ch[1]].value += Sp[rt].lazy;
        }
        Sp[rt].lazy = 0;
    }
    if (Sp[rt].rev) {
        if (Sp[rt].ch[0]) {
            Sp[Sp[rt].ch[0]].rev ^= 1;
            swap(Sp[Sp[rt].ch[0]].ch[0], Sp[Sp[rt].ch[0]].ch[1]);
        }
        if (Sp[rt].ch[1]) {
            Sp[Sp[rt].ch[1]].rev ^= 1;
            swap(Sp[Sp[rt].ch[1]].ch[0], Sp[Sp[rt].ch[1]].ch[1]);
        }
        Sp[rt].rev = 0;
    }
}

int id(int x) {
    return Sp[Sp[x].fa].ch[1] == x;
}
void link(int son, int fa, int k) {
    Sp[son].fa = fa; Sp[fa].ch[k] = son;
}

void rotate(int  x) {
    int y = Sp[x].fa;
    int z = Sp[y].fa;
    int yk = id(x);
    int zk = id(y);
    int b = Sp[x].ch[yk ^ 1];
    link(b, y, yk); link(y, x, yk ^ 1);
    link(x, z, zk);
    pushup(y); pushup(x);
}

void SPLAY(int x, int aim) {
    while (Sp[x].fa != aim) {
        int y = Sp[x].fa;
        int z = Sp[y].fa;
        if (z != aim)id(x) == id(y) ? rotate(y) : rotate(x);
        rotate(x);
    }
    if (aim == 0)root = x;
}

int kth(int k) {
    int now = root;
    while (1) {
        pushdown(now);
        int left = Sp[now].ch[0];
        if (Sp[left].size + 1 < k) {
            k -= Sp[left].size + 1; now = Sp[now].ch[1];
        }
        else if (Sp[left].size >= k)now = left;
        else return now;
    }
}

int build(int l, int r, int fa) {
    if (l > r)return 0;
    if (l == r) {
        Sp[l].fa = fa; Sp[l].maxx = Sp[l].value = a[l];
        Sp[l].size = 1; return l;
    }
    int mid = (l + r) >> 1;
    Sp[mid].ch[0] = build(l, mid - 1, mid);
    Sp[mid].ch[1] = build(mid + 1, r, mid);
    Sp[mid].value = a[mid];
    Sp[mid].fa = fa;
    pushup(mid);
    return mid;
}

int split(int l, int r) {
    l = kth(l); r = kth(r + 2);
    SPLAY(l, 0); SPLAY(r, l);
    return Sp[Sp[root].ch[1]].ch[0];
}

void upd(int l, int  r, int v) {
    int now = split(l, r);
    Sp[now].lazy += v; Sp[now].maxx += v; Sp[now].value += v;
    pushup(Sp[root].ch[1]); pushup(root);
}

void Reverse(int l, int r) {
    int now = split(l, r);
    Sp[now].rev ^= 1;
    swap(Sp[now].ch[0], Sp[now].ch[1]);
    pushup(Sp[root].ch[1]); pushup(root);
}
int query(int l, int  r) {
    return Sp[split(l, r)].maxx;
}

void dfs(int rt) {
    pushdown(rt);
    if (Sp[rt].ch[0])dfs(Sp[rt].ch[0]);
    if (Sp[rt].value != inf && Sp[rt].value != -inf) {
        cout << Sp[rt].value << ' ';
    }
    if (Sp[rt].ch[1])dfs(Sp[rt].ch[1]);
}

int main()
{
    //ios::sync_with_stdio(0);
    rdint(n); rdint(m);
    for (int i = 2; i <= n + 1; i++)a[i] = i - 1;
    a[1] = -inf; a[n + 2] = inf;
    root = build(1, n + 2, 0);
    while (m--) {
        int l, r; rdint(l); rdint(r);
        Reverse(l, r);
    }
    dfs(root); cout << endl;
    return 0;
}

EPFL - Fighting