POJ3468 本来是一道线段树

// 然而博主用 Splay Tree 做的，4000+ ms。。。飘过

#include "cstdio"
using namespace std;
long long in[100010];
const int INF = 1 << 28;

struct Node {
    Node *pre, *ch[2];
    long long sz, val;
    long long sum, add;
} *null, *root, buf[100010];
int idx;

Node *usdNode[100010];
int top;

inline void PushDown(Node *p)
{
    if (p == null) {
        return ;
    }
    if(p->add) {
        p->sum += p->add * p->sz;
        p->val += p->add;
        if(p->ch[0] != null) {
            p->ch[0]->add += p->add;
        }
        if(p->ch[1] != null) {
            p->ch[1]->add += p->add;
        }
        p->add = 0;
    }
}

inline void Update(Node *p)
{
    if (p == null) {
        return ;
    }
    PushDown(p);
    PushDown(p->ch[0]);
    PushDown(p->ch[1]);
    p->sz = p->ch[0]->sz + p->ch[1]->sz + 1;
    p->sum = p->ch[0]->sum + p->ch[1]->sum + p->val;
}

Node *AddNode(int val)
{
    Node *p;
    if (top) {
        p = usdNode[top];
        --top;
    } else {
        ++idx;
        p = &buf[idx];
    }
    p->pre = p->ch[0] = p->ch[1] = null;
    p->sz = 1, p->val = val;

    p->add = 0;
    p->sum = val;
    return p;
}

void Init()
{
    idx = top = 0;
    null = AddNode(-INF);
    null->sz = 0;
    null->sum = 0;
    root = AddNode(-INF);

    root->sum = 0;
    Node *p;

    p = AddNode(-INF);
    p->sum = 0;

    root->ch[1] = p;
    p->pre = root;
    Update(root->ch[1]);
    Update(root);
}

void Rotate(Node *p, bool c)
{
    Node *f = p->pre;
    PushDown(f);
    PushDown(p);
    f->ch[!c] = p->ch[c];
    if (p->ch[c] != null) {
        p->ch[c]->pre = f;
    }
    p->pre = f->pre;
    if (f->pre != null) {
        if (f->pre->ch[0] == f) {
            f->pre->ch[0] = p;
        } else {
            f->pre->ch[1] = p;
        }
    }
    p->ch[c] = f;
    f->pre = p;
    if (f == root) {
        root = p;
    }
    Update(f);
}

void Splay(Node *p, Node *tf)
{
    Node *f, *ff;
    PushDown(p);
    while (p->pre != tf) {
        f = p->pre, ff = f->pre;
        if (ff == tf) {
            Rotate(p, p->pre->ch[0] == p);
        } else {
            if (ff->ch[0] == f) {
                if (f->ch[0] == p) {
                    Rotate(f, 1);
                    Rotate(p, 1);
                } else {
                    Rotate(p, 0);
                    Rotate(p, 1);
                }
            } else {
                if (f->ch[1] == p) {
                    Rotate(f, 0);
                    Rotate(p, 0);
                } else {
                    Rotate(p, 1);
                    Rotate(p, 0);
                }
            }
        }
        Update(p);
    }
}

Node *Build(int l, int r)
{
    if (l > r) {
        return null;
    }
    int mid = (l + r) >> 1;
    Node *p = AddNode(in[mid]);
    p->ch[0] = Build(l, mid - 1);
    if (p->ch[0] != null) {
        p->ch[0]->pre = p;
    }
    p->ch[1] = Build(mid + 1, r);
    if (p->ch[1] != null) {
        p->ch[1]->pre = p;
    }
    Update(p);
    return p;
}

Node *Select(int kth)
{
    int tmp;
    Node *p = root;
    while (1) {
        PushDown(p);
        tmp = p->ch[0]->sz;
        if (tmp + 1 == kth) {
            break;
        }
        if (kth <= tmp) {
            p = p->ch[0];
        } else {
            kth -= tmp + 1;
            p = p->ch[1];
        }
    }
    return p;
}

void SegAdd(int pos, int tot, long long delte)
{
    Splay(Select(pos - 1), null);
    Splay(Select(pos + tot), root);
    if (root->ch[1]->ch[0] != null) {
        root->ch[1]->ch[0]->add += delte;
        Splay(root->ch[1]->ch[0], null);
    }
}

void GetSum(int pos, int tot)
{
    Splay(Select(pos - 1), null);
    Splay(Select(pos + tot), root);
    printf("%lld
",root->ch[1]->ch[0]->sum);
}

int N, Q;
char cmd[10];

int main()
{
    int i;
    scanf("%d%d", &N, &Q);
    Init();
    for(i = 1; i <= N; ++i) {
        scanf("%lld", &in[i]);
    }
    Node *tRoot = Build(1, N);
    root->ch[1]->ch[0] = tRoot;
    tRoot->pre = root->ch[1];
    Update(root->ch[1]);
    Update(root);

    int l, r;
    long long c;
    while(Q--) {
        scanf("%s", cmd);
        switch(cmd[0]) {
        case 'Q':
            scanf("%d%d", &l, &r);
            GetSum(l + 1, r - l + 1);
            break;
        case 'C':
            scanf("%d%d%lld", &l, &r, &c);
            SegAdd(l + 1, r - l + 1, c);
        }
    }
}