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。。。

 

  1 /**************************************************************
  2     Problem: 1593
  3     User: rausen
  4     Language: C++
  5     Result: Accepted
  6     Time:388 ms
  7     Memory:4404 kb
  8 ****************************************************************/
  9  
 10 #include <cstdio>
 11 #include <algorithm>
 12  
 13 using namespace std;
 14  
 15 inline int read();
 16  
 17 struct seg {
 18     seg *ls, *rs;
 19     int mxl, mxm, mxr, len, tag;
 20      
 21     #define Len (1 << 16)
 22     void* operator new(size_t, int x) {
 23         static seg *mempool, *c;
 24         if (c == mempool)
 25             mempool = (c = new seg[Len]) + Len;
 26         c -> ls = c -> rs = NULL;
 27         c -> mxl = c -> mxr = c -> mxm = c -> len = x, c -> tag = -1;
 28         return c++;     
 29     }
 30     #undef Len
 31      
 32     #define mid (l + r >> 1)
 33     #define Ls this -> ls
 34     #define Rs this -> rs    
 35     inline void fill(int d) {
 36         if (d) this -> mxl = this -> mxr = this -> mxm = 0;
 37         else this -> mxl = this -> mxr = this -> mxm = this -> len;
 38         this -> tag = d;
 39     }
 40      
 41     inline void push() {
 42         if (~this -> tag) {
 43             if (Ls) Ls -> fill(this -> tag);
 44             if (Rs) Rs -> fill(this -> tag);
 45             this -> tag = -1;
 46         }
 47     }
 48     inline void update() {
 49         this -> mxl = Ls -> mxl + (Ls -> mxl == Ls -> len ? Rs -> mxl : 0);
 50         this -> mxr = Rs -> mxr + (Rs -> mxr == Rs -> len ? Ls -> mxr : 0);
 51         this -> mxm = max(max(Ls -> mxm, Rs -> mxm), Ls -> mxr + Rs -> mxl);
 52     }
 53      
 54     void build(int l, int r) {
 55         if (l == r) return;
 56         Ls = new(mid - l + 1)seg, Ls -> build(l, mid);
 57         Rs = new(r - mid)seg, Rs -> build(mid + 1, r);
 58     }
 59      
 60     void modify(int l, int r, int L, int R, int d) {
 61         if (L <= l && r <= R) {
 62             this -> fill(d);
 63             return;
 64         }
 65         this -> push();
 66         if (L <= mid) Ls -> modify(l, mid, L, R, d);
 67         if (mid < R) Rs -> modify(mid + 1, r, L, R, d);
 68         this -> update();
 69     }
 70      
 71     int query(int l, int r, int len) {
 72         this -> push();
 73         if (this -> mxm < len) return 0;
 74         if (Ls -> mxm >= len) return Ls -> query(l, mid, len);
 75         if (Ls -> mxr + Rs -> mxl >= len) return mid - Ls -> mxr + 1;
 76         if (Rs -> mxm >= len) return Rs -> query(mid + 1, r, len);
 77     }
 78     #undef mid
 79     #undef Ls
 80     #undef Rs
 81 } *segment;
 82  
 83 int n, m;
 84  
 85 int main() {
 86     int i, oper, x, y;
 87     n = read(), m = read();
 88     segment = new(n)seg;
 89     segment -> build(1, n);
 90     for (i = 1; i <= m; ++i) {
 91         oper = read();
 92         if (oper == 1) {
 93             x = segment -> query(1, n, y = read());
 94             printf("%d\n", x);
 95             if (x) segment -> modify(1, n, x, x + y - 1, 1);
 96         } else {
 97             x = read(), y = read();
 98             segment -> modify(1, n, x, x + y - 1, 0);
 99         }
100     }
101     return 0;
102 }
103  
104 inline int read() {
105     static int x;
106     static char ch;
107     x = 0, ch = getchar();
108     while (ch < '0' || '9' < ch)
109         ch = getchar();
110     while ('0' <= ch && ch <= '9') {
111         x = x * 10 + ch - '0';
112         ch = getchar();
113     }
114     return x;
115 }
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posted on 2015-04-26 22:59  Xs酱~  阅读(388)  评论(0)  编辑  收藏  举报