BZOJ1251——序列终结者

给你一个数列，让你实现区间加上一个值，区间翻转，区间最大值

裸splay，懒标记一发即可

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
using namespace std;
struct Node{
    Node *ch[2];
    int m, v, k, s, f;
    inline int cmp(int x){
        int o = 0;
        if(ch[0] != NULL){
            if(ch[0] -> s >= x) return 0;
            o += ch[0] -> s;
        }
        if(o + 1 == x) return -1;
        return 1;
    }
    inline void maintain(){
        s = 1;
        if(ch[0] != NULL) s += ch[0] -> s;
        if(ch[1] != NULL) s += ch[1] -> s;
        return;
    }
    inline void Back(){
        m = v;
        if(ch[0] != NULL) m = max(m, ch[0] -> m);
        if(ch[1] != NULL) m = max(m, ch[1] -> m);
        return;
    }
    inline void pushdown(){
        if(f == 1){
            if(ch[0] != NULL){
                ch[0] -> f ^= 1;
                swap(ch[0] -> ch[0], ch[0] -> ch[1]);
            }
            if(ch[1] != NULL){
                ch[1] -> f ^= 1;
                swap(ch[1] -> ch[0], ch[1] -> ch[1]);
            }
            f = 0;
        }
        if(ch[0] != NULL){
            ch[0] -> k += k;
            ch[0] -> m += k;
            ch[0] -> v += k;
        }
        if(ch[1] != NULL){
            ch[1] -> k += k;
            ch[1] -> m += k;
            ch[1] -> v += k;
        }
        k = 0;
        return;
    }
};
struct splay_tree{
    Node ft[1000000];
    int size;
    Node *p;
    int x, y;
    inline void init(){
        size = 0;
        return;
    }
    inline void rotate(Node* &o, int d){
        Node *k = o -> ch[d ^ 1];
        k -> pushdown(); //注意这里
        o -> ch[d ^ 1] = k -> ch[d];
        k -> ch[d] = o;
        o -> maintain();
        k -> maintain();
        o -> Back();
        k -> Back();
        o = k;
        return;
    }
    inline void splay(Node* &o, int k){
        o -> pushdown();
        if(o -> ch[0] != NULL) o -> ch[0] -> pushdown();
        if(o -> ch[1] != NULL) o -> ch[1] -> pushdown();
        int d = o -> cmp(k);
        if(d == 1 && o -> ch[0] != NULL) k = k - o -> ch[0] -> s - 1;
        else if(d == 1) k --;
        if(d != -1){
            Node* w = o -> ch[d];
            int d2 = w -> cmp(k);
            int k2 = k;
            if(d2 != 0){
                k2 --;
                if(w -> ch[0] != NULL) k2 -= w -> ch[0] -> s;
            }
            if(d2 != -1){
                splay(w -> ch[d2], k2);
                if(d == d2) rotate(o, d ^ 1);
                else rotate(o -> ch[d], d);
            }
            rotate(o, d ^ 1);
        }
        if(o -> ch[0] != NULL) o -> ch[0] -> pushdown();
        if(o -> ch[1] != NULL) o -> ch[1] -> pushdown();
        o -> Back();
        return;
    }
    inline Node* merge(Node *left, Node *right){
        if(left == NULL) return right;
        if(right == NULL) return left;
        splay(left, left -> s);
        left -> ch[1] = right;
        left -> maintain();
        left -> Back();
        return left;
    }
    inline void split(Node* &o, int k, Node* &left, Node* &right){
        if(k == 0){
            left = NULL;
            right = o;
            return;
        }
        splay(o, k);
        left = o;
        right = o -> ch[1];
        left -> ch[1] = NULL;
        left -> maintain();
        left -> Back();
        return;
    }
    inline void insert(Node* &o, int l, int r){
        if(r < l) return;
        int mid = (l + r) / 2;
        o = &ft[size]; size ++;
        o -> ch[0] = o -> ch[1] = NULL;
        o -> v = o -> m = o -> f = o -> k = 0;
        if(l != r){
            insert(o -> ch[0], l, mid - 1);
            insert(o -> ch[1], mid + 1, r);
        }
        o -> maintain();
        return;
    }
    inline void add1(Node* &o, int l, int r, int t){
        if(r < l) return;
        o -> pushdown();
        if(y < l || r < x) return;
        if(x <= l && r <= y){
            o -> m += t;
            o -> v += t;
            o -> k += t;
            return;
        }
        int mid = l;
        if(o -> ch[0] != NULL) mid += o -> ch[0] -> s;
        if(x <= mid && mid <= y) o -> v += t;
        if(o -> ch[0] != NULL) add1(o -> ch[0], l, mid - 1, t);
        if(o -> ch[1] != NULL) add1(o -> ch[1], mid + 1, r, t);
        o -> Back();
        return;
    }
    inline void add2(Node* &o, int l, int r){
        Node *left, *mid, *right;
        split(p, l - 1, left, mid);
        split(mid, r - l + 1, mid, right);
        swap(mid -> ch[0], mid -> ch[1]);
        mid -> f ^= 1;//注意这里
        p = merge(left, merge(mid, right));
        return;
    }
    inline int query(Node* &o, int l, int r){
        if(r < l) return -2147483640;
        o -> pushdown();
        if(y < l || r < x) return -214743640;
        if(x <= l && r <= y) return o -> m;
        int mid = l;
        if(o -> ch[0] != NULL) mid += o -> ch[0] -> s;
        int ret = -2147483640;
        if(x <= mid && mid <= y) ret = o -> v;
        if(o -> ch[0] != NULL) ret = max(ret, query(o -> ch[0], l, mid - 1));
        if(o -> ch[1] != NULL) ret = max(ret, query(o -> ch[1], mid + 1, r));
        o -> Back();
        return ret;
    }
} wt;
int main(){
    /*freopen("seq1.in", "r", stdin);
    freopen("seq.out", "w", stdout);*/
    int n, m;
    scanf("%d%d", &n, &m);
    wt.insert(wt.p, 1, n);
    for(int i = 1; i <= m; i ++){
        int o;
        int a, b, c;
        scanf("%d", &o);
        if(o == 1){
            scanf("%d%d%d", &a, &b, &c);
            wt.x = a; wt.y = b;
            wt.add1(wt.p, 1, n, c);
        }
        else if(o == 2){
            scanf("%d%d", &a, &b);
            wt.add2(wt.p, a, b);
        }
        else{
            scanf("%d%d", &a, &b);
            wt.x = a; wt.y = b;
            printf("%d\n", wt.query(wt.p, 1, n));
        }
    }
    return 0;
}