洛谷 2471 BZOJ 1067 [SCOI2007]降雨量

 1 #include<cstdio>
 2 #include<algorithm>
 3 #define rg register
 4 #define N 50010
 5 #define ls (u<<1)
 6 #define rs (u<<1|1) 
 7 using namespace std;
 8 int n,m,y[N],R[N];
 9 struct tree{
10     int l,r,mx;
11 }a[N<<2];
12 inline int read(){
13     int k=0,f=1; char c=getchar();
14     while(c<‘0‘||c>‘9‘)c==‘-‘&&(f=-1),c=getchar();
15     while(‘0‘<=c&&c<=‘9‘)k=k*10+c-‘0‘,c=getchar();
16     return k*f;
17 }
18 void build(int u,int l,int r){
19     a[u].l=l; a[u].r=r;
20     if(l<r){
21         int mid=(l+r)>>1;
22         build(ls,l,mid); build(rs,mid+1,r);
23         a[u].mx=max(a[ls].mx,a[rs].mx);
24     }
25     else a[u].mx=R[l];
26 }
27 int query(int u,int l,int r){
28     if(l<=a[u].l&&a[u].r<=r) return a[u].mx;
29     int ret=-2e9,mid=(a[u].l+a[u].r)>>1;
30     if(l<=mid) ret=max(ret,query(ls,l,r));
31     if(r>mid) ret=max(ret,query(rs,l,r));
32     return ret;
33 }
34 int main(){
35     n=read();
36     for(rg int i=1;i<=n;i++) y[i]=read(),R[i]=read();
37     build(1,1,n);
38     m=read();
39     for(rg int i=1,Mx,l2,r2;i<=m;i++){
40         int l=read(),r=read();
41         l2=lower_bound(y+1,y+1+n,l)-y;
42         r2=lower_bound(y+1,y+1+n,r)-y;
43         Mx=-2e9;
44         if(y[l2]!=l&&y[r2]!=r){
45             puts("maybe"); continue;
46         }
47         if(y[l2]==l&&y[r2]!=r){
48             if(r2-1>=l2+1) Mx=query(1,l2+1,r2-1);
49             if(Mx>=R[l2]) puts("false");
50             else puts("maybe");
51         }
52         if(y[l2]!=l&&y[r2]==r){
53             if(r2-1>=l2) Mx=query(1,l2,r2-1);
54             if(Mx>=R[r2]) puts("false");
55             else puts("maybe");
56         }
57         if(y[l2]==l&&y[r2]==r){
58             if(r2-1>=l2+1) Mx=query(1,l2+1,r2-1);
59             if(Mx>=R[r2]||R[l2]<R[r2]){
60                 puts("false"); continue;
61             }
62             if(y[r2]-y[l2]>r2-l2){
63                 puts("maybe"); continue;
64             }
65             puts("true");
66         }
67     }
68     return 0;
69 }