【HDOJ】3487 Play with Chain

Splay入门题目，区间翻转，区间分割。

/*  */
#include <iostream>
#include <string>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#include <deque>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <climits>
#include <cctype>
#include <cassert>
#include <functional>
#include <iterator>
#include <iomanip>
using namespace std;
//#pragma comment(linker,"/STACK:102400000,1024000")

#define sti                set<int>
#define stpii            set<pair<int, int> >
#define mpii            map<int,int>
#define vi                vector<int>
#define pii                pair<int,int>
#define vpii            vector<pair<int,int> >
#define rep(i, a, n)     for (int i=a;i<n;++i)
#define per(i, a, n)     for (int i=n-1;i>=a;--i)
#define clr                clear
#define pb                 push_back
#define mp                 make_pair
#define fir                first
#define sec                second
#define all(x)             (x).begin(),(x).end()
#define SZ(x)             ((int)(x).size())
#define lson            l, mid, rt<<1
#define rson            mid+1, r, rt<<1|1
#define grandlson        ch[ch[root][1]][0]

const int maxn = 3e5+5;
int pre[maxn], ch[maxn][2], root, tot;
int key[maxn], s[maxn], rev[maxn];
int stk[maxn], top;
int n, m, cnt;

void newNode(int& r, int fa, int k) {
    if (top)
        r = stk[top--];
    else
        r = ++tot;
    key[r] = k;
    pre[r] = fa;
    rev[r] = 0;
    ch[r][0] = ch[r][1] = 0;
    s[r] = 1;
}

void PushUp(int r) {
    s[r] = s[ch[r][0]] + s[ch[r][1]] + 1;
}

void UpdateRev(int rt) {
    if (rt == 0)    return ;
    swap(ch[rt][0], ch[rt][1]);
    rev[rt] ^= 1;
}

void PushDown(int rt) {
    if (rev[rt]) {
        UpdateRev(ch[rt][0]);
        UpdateRev(ch[rt][1]);
        rev[rt] = 0;
    }
}

void Build(int& rt, int l, int r, int fa) {
    if (l > r)    return ;
    
    int mid = (l + r) >> 1;
    
    newNode(rt, fa, mid);
    Build(ch[rt][0], l, mid-1, rt);
    Build(ch[rt][1], mid+1, r, rt);
    PushUp(rt);
}

void inorder(int rt) {
    if (rt == 0)    return ;
    inorder(ch[rt][0]);
    printf("s = %d, key = %d\n", s[rt], key[rt]);
    inorder(ch[rt][1]);
}

void init() {
    root = tot = top = 0;
    ch[0][0] = ch[0][1] = s[0] = key[0] = pre[0] = rev[0] = 0;
    newNode(root, 0, -1);
    newNode(ch[root][1], root, -1);
    Build(grandlson, 1, n, ch[root][1]);
    PushUp(ch[root][1]);
    PushUp(root);
    #ifndef ONLINE_JUDGE
        inorder(root);
    #endif
}

void Rotate(int x, int d) {
    int y = pre[x];
    
    PushDown(y);
    PushDown(x);
    ch[y][d^1] = ch[x][d];
    pre[ch[x][d]] = y;
    if (pre[y])
        ch[pre[y]][ch[pre[y]][1]==y] = x;
    pre[x] = pre[y];
    pre[y] = x;
    ch[x][d] = y;
    PushUp(y);
}

void Splay(int r, int goal) {
    PushDown(r);
    while (pre[r] != goal) {
        if (pre[pre[r]] == goal) {
            PushDown(pre[r]);
            PushDown(r);
            Rotate(r, ch[pre[r]][0]==r);
        } else {
            PushDown(pre[pre[r]]);
            PushDown(pre[r]);
            PushDown(r);
            int y = pre[r];
            int d = ch[pre[y]][0]==y;
            if (ch[y][d] == r) {
                Rotate(r, d^1);
                Rotate(r, d);
            } else {
                Rotate(y, d);
                Rotate(r, d);
            }
        }
    }
    PushUp(r);
    if (goal == 0)
        root = r;
}

int kth(int r, int k) {
    PushDown(r);
    int t = s[ch[r][0]] + 1;
    
    if (t == k)
        return r;
    else if (k < t)
        return kth(ch[r][0], k);
    else
        return kth(ch[r][1], k-t);
}

void cut(int l, int r, int c) {
    Splay(kth(root, l), 0);
    Splay(kth(root, r+2), root);
    int tmp = grandlson;
    grandlson = 0;
    PushUp(ch[root][1]);
    PushUp(root);
    Splay(kth(root, c+1), 0);
    Splay(kth(root, c+2), root);
    grandlson = tmp;
    pre[tmp] = ch[root][1];
    PushUp(ch[root][1]);
    PushUp(root);
}

void flip(int l, int r) {
    Splay(kth(root, l), 0);
    Splay(kth(root, r+2), root);
    UpdateRev(grandlson);
    PushUp(ch[root][1]);
    PushUp(root);
}

void print(int rt) {
    if (!rt)    return ;
    
    PushDown(rt);
    print(ch[rt][0]);
    if (cnt>=1 && cnt<=n) {
        if (cnt < n)
            printf("%d ", key[rt]);
        else
            printf("%d\n", key[rt]);
    }
    ++cnt;
    print(ch[rt][1]);
}

int main() {
    ios::sync_with_stdio(false);
    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
        freopen("data.out", "w", stdout);
    #endif
    
    char cmd[7];
    int a, b, c;
    
    while (scanf("%d %d", &n, &m) != EOF) {
        if (n<0 && m<0)
            break;
        init();
        while (m--) {
            scanf("%s %d %d", cmd, &a, &b);
            if (cmd[0] == 'C') {
                scanf("%d", &c);
                cut(a, b, c);
            } else {
                flip(a, b);
            }
        }
        cnt = 0;
        print(root);
    }
    
    #ifndef ONLINE_JUDGE
        printf("time = %d.\n", (int)clock());
    #endif
    
    return 0;
}