POJ A Simple Problem with Integers (Splay 伸展树 入门)

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/***   Splay 2657 ms*   刚入手 splay,这题做第三遍了。 先是线段树,然后树状数组,这次Splay*       写的挺顺,也1A。就是手有点抽筋 -__-。。*   算入门题吧,不过树状数组那思路挺不错的。*   这次就记splay,如果是用splay的话就大水了。 不过效率也低,比线段树还低。*   思路的话,就是用splay维护个sum域,再打个lazy-tag*   (这里用add表示以该顶点为树根的树表示的区间所需要添加的值。val表示该点的值)*   然后维护sum和add,每次push_down()就行了。。其实思想还是和线段树一样的**      还有点,就是在维护区间的时候,把下标都加一。*   也就是在存数的时候,num[1] 和 num[n+2] 等于0.*   所有的数都存在 2 ~ n+1 的区间。*   因为在对区间询问的时候,Q l r*   在调整splay的时候要把 l-1的节点旋转到root,而r+1要转到root下*   如果是询问整个区间 Q 1 n, 则需要把下标为0的节点旋转至跟。这样就不好维护size域了*       最后注意输出的时候要long long型的。*/#include <cstdio>#include <iostream>#include <cstring>#include <cmath>#include <string>#include <queue>#include <map>#include <vector>#include <algorithm>#define DEBUG 0#define INF 0x3fffffff#define OUTSTARS  printf("*****************************\n");#define MAXN 100005typedef long long LL;using namespace std;struct Splay{    LL val, size, add, sum;    Splay *son[2], *fa;    void init()    {        size = 1; add = sum = 0;        son[0] = son[1] = fa = NULL;    }    void rot(int c)    {        Splay *y = fa, *z = fa->fa;        y->son[!c] = son[c]; if(son[c]) son[c]->fa = y;        fa = z;        if(z) {            if(z->son[0] == y) z->son[0] = this;            else z->son[1] = this;        }        son[c] = y; y->fa = this;        y->update();    }    void splay(Splay *pa)    {        for(push_down(); fa != pa; )        {            if(fa->fa == pa) {                if(fa->son[0] == this) rot(1);                else rot(0);            } else {                Splay *y = fa, *z = fa->fa;                if(z->son[0] == y) {                    if(y->son[0] == this) {                        y->rot(1); rot(1);                    } else {                        rot(0); rot(1);                    }                } else {                    if(y->son[1] == this) {                        y->rot(0); rot(0);                    } else {                        rot(1); rot(0);                    }                }            }            update();        }    }    void update()    {        size = 1; sum = val;        if(son[0]) {            size += son[0]->size;            sum += son[0]->sum;        }        if(son[1]) {            size += son[1]->size;            sum += son[1]->sum;        }    }    void push_down()    {        if(!add) return ;        if(son[0]) {            son[0]->add += add;            son[0]->val += add;            son[0]->sum += son[0]->size * add;        }        if(son[1]) {            son[1]->add += add;            son[1]->val += add;            son[1]->sum += son[1]->size * add;        }        add = 0;    }    Splay *find(int x)    {        int L = 0;        push_down();        if(son[0])            L += son[0]->size;        if(x <= L) return son[0]->find(x);        if(x == L + 1) return this;        return son[1]->find(x - L - 1);    }}tree[MAXN];int n, m, id;int num[MAXN];Splay *root;Splay *_alloc() { tree[id].init(); return &tree[id++]; }Splay *build(int l, int r){    if(l > r) return NULL;    int mid = (l + r) >> 1;    Splay *cur = _alloc();    cur->val = num[mid];    cur->son[0] = build(l, mid - 1);    cur->son[1] = build(mid + 1, r);    if(cur->son[0]) cur->son[0]->fa = cur;    if(cur->son[1]) cur->son[1]->fa = cur;    cur->update();    return cur;}void add(int L, int R, int d){    Splay *tmp;    tmp = root->find(L - 1);    tmp->splay(NULL); root = tmp;    tmp = root->find(R + 1);    tmp->splay(root);    tmp = root->son[1]->son[0];    tmp->push_down();    tmp->add = d;    tmp->sum += tmp->size * d;    tmp->val += d;}LL query(int L, int R){    Splay *tmp = root->find(L - 1);    tmp->splay(NULL); root = tmp;    tmp = root->find(R + 1);    tmp->splay(root);    tmp = root->son[1]->son[0];    return tmp->sum;}int main(){    while(~scanf("%d%d", &n, &m))    {        id = 0;        num[1] = num[n+2] = 0;        for(int i = 2; i <= n + 1; i ++)            scanf("%d", &num[i]);        root = build(1, n + 2);        for(int i = 0; i < m; i ++)        {            getchar();            char cmd = getchar();            if(cmd == 'C')            {                int l, r, d;                scanf("%d%d%d", &l, &r, &d);                l ++, r ++;                add(l, r, d);            } else {                int l, r;                scanf("%d%d", &l, &r);                l ++, r ++;                printf("%I64d\n", query(l, r));            }        }    }    return 0;}


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