BZOJ1593 [Usaco2008 Feb]Hotel 旅馆

裸上线段树，就是记的东西有点多。。。

每个点记区间左端最长0，右端最长0，中间最长0，和tag表示是否全为0/1

直接更新就好，查询的时候先查左儿子，然后查中间，最后查右儿子。。。

 /**************************************************************
     Problem: 1593
     User: rausen
     Language: C++
     Result: Accepted
     Time:388 ms
     Memory:4404 kb
 ****************************************************************/

 #include <cstdio>
 #include <algorithm>

 using namespace std;

 inline int read();

 struct seg {
     seg *ls, *rs;
     int mxl, mxm, mxr, len, tag;

     #define Len (1 << 16)
     void* operator new(size_t, int x) {
         static seg *mempool, *c;
         if (c == mempool)
             mempool = (c = new seg[Len]) + Len;
         c -> ls = c -> rs = NULL;
         c -> mxl = c -> mxr = c -> mxm = c -> len = x, c -> tag = -;
         return c++;
     }
     #undef Len

     #define mid (l + r >> 1)
     #define Ls this -> ls
     #define Rs this -> rs
     inline void fill(int d) {
         if (d) this -> mxl = this -> mxr = this -> mxm = ;
         else this -> mxl = this -> mxr = this -> mxm = this -> len;
         this -> tag = d;
     }

     inline void push() {
         if (~this -> tag) {
             if (Ls) Ls -> fill(this -> tag);
             if (Rs) Rs -> fill(this -> tag);
             this -> tag = -;
         }
     }
     inline void update() {
         this -> mxl = Ls -> mxl + (Ls -> mxl == Ls -> len ? Rs -> mxl : );
         this -> mxr = Rs -> mxr + (Rs -> mxr == Rs -> len ? Ls -> mxr : );
         this -> mxm = max(max(Ls -> mxm, Rs -> mxm), Ls -> mxr + Rs -> mxl);
     }

     void build(int l, int r) {
         if (l == r) return;
         Ls = new(mid - l + )seg, Ls -> build(l, mid);
         Rs = new(r - mid)seg, Rs -> build(mid + , r);
     }

     void modify(int l, int r, int L, int R, int d) {
         if (L <= l && r <= R) {
             this -> fill(d);
             return;
         }
         this -> push();
         if (L <= mid) Ls -> modify(l, mid, L, R, d);
         if (mid < R) Rs -> modify(mid + , r, L, R, d);
         this -> update();
     }

     int query(int l, int r, int len) {
         this -> push();
         if (this -> mxm < len) return ;
         if (Ls -> mxm >= len) return Ls -> query(l, mid, len);
         if (Ls -> mxr + Rs -> mxl >= len) return mid - Ls -> mxr + ;
         if (Rs -> mxm >= len) return Rs -> query(mid + , r, len);
     }
     #undef mid
     #undef Ls
     #undef Rs
 } *segment;

 int n, m;

 int main() {
     int i, oper, x, y;
     n = read(), m = read();
     segment = new(n)seg;
     segment -> build(, n);
     for (i = ; i <= m; ++i) {
         oper = read();
         if (oper == ) {
             x = segment -> query(, n, y = read());
             printf("%d\n", x);
             if (x) segment -> modify(, n, x, x + y - , );
         } else {
             x = read(), y = read();
             segment -> modify(, n, x, x + y - , );
         }
     }
     return ;
 }

 inline int read() {
     static int x;
     static char ch;
     x = , ch = getchar();
     while (ch < '' || '' < ch)
         ch = getchar();
     while ('' <= ch && ch <= '') {
         x = x *  + ch - '';
         ch = getchar();
     }
     return x;
 }