bzoj 1067: [SCOI2007]降雨量

Posted 2021-02-05 lxy8584099

线段树  胡乱判断法。。。

 

/**************************************************************
    Problem: 1067
    User: lxy8584099
    Language: C++
    Result: Accepted
    Time:172 ms
    Memory:5396 kb
****************************************************************/
 
#include<bits/stdc++.h>
#define il inline
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define For(i,a,b) for(int (i)=(a);(i)<=(b);(i)++)
#define Max(a,b) ((a)>(b)?(a):(b))
using namespace std;
const int N=200005;
int n,m,num[N],ls[N],rs[N];
int ye[N],co[N];
bool f[N];
struct node{
    int ans,f;
};
 
il int gi(){
    int a=0;char x=getchar();bool f=0;
    while((x<‘0‘||x>‘9‘)&&x!=‘-‘)x=getchar();
    if(x==‘-‘)x=getchar(),f=1;
    while(x>=‘0‘&&x<=‘9‘)a=(a<<3)+(a<<1)+x-48,x=getchar();
    return f?-a:a;
}
 
il void pushup(int rt){
    if(rs[rt<<1]==ls[rt<<1|1]-1)f[rt]=f[rt<<1]&f[rt<<1|1];
    rs[rt]=rs[rt<<1|1];ls[rt]=ls[rt<<1];
    num[rt]=Max(num[rt<<1],num[rt<<1|1]);
}
 
il void build(int l,int r,int rt){
    if(l==r){rs[rt]=ls[rt]=ye[l],num[rt]=co[l],f[rt]=1;return;}
    int m=l+r>>1;
    build(lson),build(rson);
    pushup(rt);
}
 
il node query(int L,int R,int l,int r,int rt){
    if(L<=l&&R>=r){
        node tmp;
        tmp.ans=num[rt],tmp.f=f[rt];
        return tmp;
    }
    int m=l+r>>1;
    node tmp;
    tmp.ans=0,tmp.f=1;
    if(L<=m){
        node x=query(L,R,lson);
        tmp.ans=Max(tmp.ans,x.ans);
        tmp.f&=x.f;
    }
    if(R>m){
        node x=query(L,R,rson);
        tmp.ans=Max(tmp.ans,x.ans);
        tmp.f&=x.f;
    }
    return tmp;
}
 
int main(){
    n=gi();
    For(i,1,n)ye[i]=gi(),co[i]=gi();
    build(1,n,1);
    m=gi();
    int x,y;
    while(m--){
        x=gi(),y=gi();
        if(x>=y){printf("false
");continue;}
        int st=lower_bound(ye+1,ye+n+1,x)-ye,ed=lower_bound(ye+1,ye+n+1,y)-ye;
        bool fl,fr;int op=0;
        fl=ye[st]==x,fr=ye[ed]==y;
        if(!fl)st--;
        if(st+1<=ed-1)op=query(st+1,ed-1,1,n,1).ans;
        if((op>=co[ed]&&fr)||(co[st]<co[ed]&&fl&&fr)||(op>=co[st]&&fl))printf("false
");
        else if(ed-st!=ye[ed]-ye[st]||!fr||!fl)printf("maybe
");
        else printf("true
");
    }
    return 0;
}