BZOJ1067 SCOI2007 降雨量

分类讨论是比较好的，直接脑补容易炸。

本来以为是水题，后来发现是神题……

#include<bits/stdc++.h>
#define rep(a,b,c) for(int a=b;a<=c;a++)
using namespace std;

int a[5000005],b[5000005],n,m,t1,t2,t3,t4,li[1000005],q1[1000005],q2[1000005],lcnt,r1[1000005],r2[1000005],seq[1000005];

void pushin(int p){
    li[++lcnt]=p; li[++lcnt]=p+1; li[++lcnt]=p-1;
}

void build(int p,int l,int r) {
    if(l==r) a[p]=seq[l], b[p]=(seq[l]>1e+9?0:seq[l]);
    else build(p*2,l,(l+r)/2), build(p*2+1,(l+r)/2+1,r), a[p]=max(a[p*2],a[p*2+1]), b[p]=max(b[p*2],b[p*2+1]);
}

int query(int p,int l,int r,int ql,int qr) {
    if(l>qr||r<ql) return 0;
    if(l>=ql&&r<=qr) return a[p];
    return max(query(p*2,l,(l+r)/2,ql,qr),query(p*2+1,(l+r)/2+1,r,ql,qr));
}

int query2(int p,int l,int r,int ql,int qr) {
    if(l>qr||r<ql) return 0;
    if(l>=ql&&r<=qr) return b[p];
    return max(query2(p*2,l,(l+r)/2,ql,qr),query2(p*2+1,(l+r)/2+1,r,ql,qr));
}

int main(){
    
    scanf("%d",&n);
    rep(i,1,n) scanf("%d%d",&r1[i],&r2[i]), pushin(r1[i]);
    
    scanf("%d",&m);
    rep(i,1,m) scanf("%d%d",&q1[i],&q2[i]), pushin(q1[i]), pushin(q2[i]);
    
    sort(li+1,li+lcnt+1);
    lcnt=unique(li+1,li+lcnt+1)-li-1;
    
    rep(i,1,n) r1[i]=lower_bound(li+1,li+lcnt+1,r1[i])-li;
    rep(i,1,m) q1[i]=lower_bound(li+1,li+lcnt+1,q1[i])-li, q2[i]=lower_bound(li+1,li+lcnt+1,q2[i])-li;
    
    rep(i,1,lcnt) seq[i]=2e+9;
    rep(i,1,n) seq[r1[i]]=r2[i];
    
    build(1,1,lcnt);
    
    rep(i,1,m) {
        int tmp=query(1,1,lcnt,q1[i]+1,q2[i]-1),tmp2=query2(1,1,lcnt,q1[i]+1,q2[i]-1);
        int I=seq[q1[i]],J=seq[q2[i]];
        if(I==2e+9 && J==2e+9) printf("maybe
");
        else if(I==2e+9) if(tmp2>=J) printf("false
"); else printf("maybe
");
        else if(J==2e+9) if(tmp2>=I) printf("false
"); else printf("maybe
");
        else if(J>I || tmp2>=J) printf("false
"); else if(tmp==2e+9) printf("maybe
"); else printf("true
");
    }
}