BZOJ1593 [Usaco2008 Feb]Hotel 旅馆 线段树

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <algorithm>
 4 using namespace std;
 5 const int MAXN=50001;
 6 struct Seg
 7 {
 8     int l,r,s,lazy,lx,rx,f;
 9 }Tree[MAXN<<2];
10 int n;
11 void Make_Tree(int x,int l,int r)
12 {
13     Tree[x].l=l,Tree[x].r=r;
14     if(l==r) {
15         Tree[x].s=1;Tree[x].lazy=0;Tree[x].lx=Tree[x].rx=1;
16         Tree[x].f=1;
17         return;
18     }
19     int mid=(l+r)>>1;
20     Make_Tree(x<<1,l,mid);
21     Make_Tree(x<<1|1,mid+1,r);
22     Tree[x].s=Tree[x].r-Tree[x].l+1;
23     Tree[x].lx=Tree[x].rx=Tree[x].s;
24 } 
25 void pushdown(int x)
26 {
27     int lc=x<<1,rc=x<<1|1;
28     if(Tree[x].f==1) {
29         Tree[x<<1].s=Tree[x<<1].lx=Tree[x<<1].rx=Tree[x<<1].r-Tree[x<<1].l+1;
30         Tree[x<<1|1].s=Tree[x<<1|1].lx=Tree[x<<1|1].rx=Tree[x<<1|1].r-Tree[x<<1|1].l+1;
31         Tree[x].f=0;Tree[x<<1].f=1,Tree[x<<1|1].f=1;
32     }
33     else if(Tree[x].f==2) {
34         Tree[x<<1].s=Tree[x<<1|1].s=0;
35         Tree[x<<1].lx=Tree[x<<1|1].lx=0;
36         Tree[x<<1].rx=Tree[x<<1|1].rx=0;
37         Tree[x].f=0;Tree[x<<1].f=2,Tree[x<<1|1].f=2;
38     }
39 }
40 void Modify(int x,int l,int r,int f)
41 {
42     //cout<<x<<‘ ‘<<l<<‘ ‘<<r<<Tree[x].s<<endl;
43     if(Tree[x].l==l&&Tree[x].r==r) {
44         if(f==1) Tree[x].s=Tree[x].lx=Tree[x].rx=r-l+1,Tree[x].f=1;
45         else if(f==2) Tree[x].s=Tree[x].lx=Tree[x].rx=0,Tree[x].f=2;
46         return;
47     }
48     int mid=(Tree[x].l+Tree[x].r)>>1;
49     pushdown(x);
50     if(r<=mid) Modify(x<<1,l,r,f);
51     else if(l>mid) Modify(x<<1|1,l,r,f);
52     else Modify(x<<1,l,mid,f),Modify(x<<1|1,mid+1,r,f);
53     Tree[x].s=max(Tree[x<<1].s,Tree[x<<1|1].s);
54     Tree[x].s=max(Tree[x].s,Tree[x<<1].rx+Tree[x<<1|1].lx);
55     Tree[x].lx=Tree[x<<1].lx;
56     if(Tree[x].lx==Tree[x<<1].r-Tree[x<<1].l+1) Tree[x].lx+=Tree[x<<1|1].lx;
57     Tree[x].rx=Tree[x<<1|1].rx;
58     if(Tree[x].rx==Tree[x<<1|1].r-Tree[x<<1|1].l+1) Tree[x].rx+=Tree[x<<1].rx;
59   //  cout<<‘@‘<<Tree[x].s<<‘ ‘<<x<<‘@‘<<endl;
60 }
61 int Query(int x,int k)
62 {
63     if(Tree[x].l==Tree[x].r) return Tree[x].l;
64     pushdown(x);
65     int mid=(Tree[x].l+Tree[x].r)>>1;
66     if(Tree[x<<1].s>=k) return Query(x<<1,k);
67     else if(Tree[x<<1].rx+Tree[x<<1|1].lx>=k) return mid-Tree[x<<1].rx+1;
68     else return Query(x<<1|1,k);
69 }
70 void check()
71 {
72     int i,j;
73     for(i=1;i<=n*2;i++)
74     cout<<Tree[i].l<<" "<<Tree[i].r<<" "<<Tree[i].s<<" "<<Tree[i].lx<<" "<<Tree[i].rx<<" "<<Tree[i].f<<endl;
75 }
76 int main(int argc, char *argv[])
77 {
78     int i,j,op,x,y,m;
79     scanf("%d%d",&n,&m);
80     Make_Tree(1,1,n);
81     for(i=1;i<=m;i++)
82     {
83         scanf("%d",&op);
84         if(op==1) {
85             scanf("%d",&x);
86             if(Tree[1].s<x) printf("0\n");
87             else {
88                 int ans=Query(1,x);
89                 printf("%d\n",ans);
90                 Modify(1,ans,ans+x-1,2);
91             }
92         }
93         else {
94             scanf("%d%d",&x,&y);
95             Modify(1,x,x+y-1,1);
96         }
97     }
98     return 0;
99 }