hdu 4417 Super Mario/树套树

原题链接：http://acm.hdu.edu.cn/showproblem.php?pid=4417

题意很简单，给定一个序列求一个区间 [L, R,]中小于等于H的元素的个数。

好像函数式线段树可解吧，可弱弱的沙茶一直没弄懂其精髓，只好用树套树暴力碾压了

额树套树，线段树的每一个节点套一个sb树。

当查询[l,r]区间中的值小于等于H的个数，先用线段树找到相应的区间，

然后再查询该区间下对应的平衡树中小于等于H的个数，累加即可。

一直以为会超时，结果400+ms就过了，数据应该很弱吧(自己对拍了一组(N,M)10w规模的跑了2s多o(╯□╰)o)。

 #include<cstdio>
 #include<cstdlib>
 #include<cstring>
 #include<algorithm>
 #define lc root<<1
 #define rc root<<1|1
 const int Max_N = ;
 struct SBT{
     int v, s, c;
     SBT *ch[];
     inline void set(int _v = ){
         v = _v, c = s = ;
         ch[] = ch[] = null;
     }
     inline void push_up(){
         s = ch[]->s + ch[]->s + c;
     }
     inline int cmp(int x) const{
         return v == x ? - : x > v;
     }
 }*null, stack[Max_N << ], *ptr[Max_N << ];
 int sz = , sum = , arr[Max_N];
 void init(){
     null = &stack[sz++];
     null->v = null->s = null->c = ;
 }
 inline void rotate(SBT* &x, int d){
     SBT *k = x->ch[!d];
     x->ch[!d] = k->ch[d];
     k->ch[d] = x;
     k->s = x->s;;
     x->push_up();
     x = k;
 }
 void Maintain(SBT* &x, int d){
     if (x->ch[d] == null) return;
     if (x->ch[d]->ch[d]->s > x->ch[!d]->s){
         rotate(x, !d);
     } else if (x->ch[d]->ch[!d]->s > x->ch[d]->s){
         rotate(x->ch[d], d), rotate(x, !d);
     } else {
         return;
     }
     Maintain(x, ), Maintain(x, );
 }
 void insert(SBT* &x, int v){
     if (x == null){
         x = &stack[sz++];
         x->set(v);
     } else {
         x->s++;
         int d = x->cmp(v);
         if (- == d){
             x->c++;
             return;
         }
         insert(x->ch[d], v);
         x->push_up();
         Maintain(x, d);
     }
 }
 int sbt_rank(SBT *x, int key){
     int t, cur;
     for (t = cur = ; x != null;){
         t = x->ch[]->s;
         if (key < x->v) x = x->ch[];
         else if (key >= x->v) cur += x->c + t, x = x->ch[];
     }
     return cur;
 }
 void seg_built(int root, int l, int r){
     ptr[root] = null;
     for (int i = l; i <= r; i++) insert(ptr[root], arr[i]);
     if (l == r) return;
     int mid = (l + r) >> ;
     seg_built(lc, l, mid);
     seg_built(rc, mid + , r);
 }
 void seg_rank(int root, int l, int r, int x, int y, int v){
     if (x > r || y < l) return;
     if (x <= l && y >= r){
         sum += sbt_rank(ptr[root], v);
         return;
     }
     int mid = (l + r) >> ;
     seg_rank(lc, l, mid, x, y, v);
     seg_rank(rc, mid + , r, x, y, v);
 }
 int main(){
 #ifdef LOCAL
     freopen("in.txt", "r", stdin);
     freopen("out.txt", "w+", stdout);
 #endif
     int i, t, n, m, a, b, c, k = ;
     scanf("%d", &t);
     while (t--){
         sz = , init();
         scanf("%d %d", &n, &m);
         printf("Case %d:\n", k++);
         for (i = ; i <= n; i++) scanf("%d", &arr[i]);
         seg_built(, , n);
         while (m--){
             scanf("%d %d %d", &a, &b, &c);
             sum = ;
             seg_rank(, , n, a + , b + , c);
             printf("%d\n", sum);
         }
     }
     return ;
 }