cogs62 [HNOI2004] 宠物收养所

cogs62 [HNOI2004] 宠物收养所


啦啦啦啦

不维护区间的平衡树题都是树状数组+二分练手题!
不会的参考我的普通平衡树的多种神奇解法之BIT+二分答案

// It is made by XZZ
#include<cstdio>
#include<algorithm>
using namespace std;
#define rep(a,b,c) for(rg int a=b;a<=c;a++)
#define drep(a,b,c) for(rg int a=b;a>=c;a--)
#define erep(a,b) for(rg int a=fir[b];a;a=nxt[a])
#define il inline
#define rg register
#define vd void
typedef long long ll;
il int gi(){
    rg int x=0;rg bool flg=0;rg char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')flg=1;ch=getchar();}
    while(ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
    return flg?-x:x;
}
const int maxn=80010;
int n;
int t[maxn],tot;
#define lb(o) (o&-o)
il vd Appear(int p){++p;while(p<=tot)++t[p],p+=lb(p);}
il vd Disappear(int p){++p;while(p<=tot)--t[p],p+=lb(p);}
il int Query(int p){int ret=0;while(p)ret+=t[p],p-=lb(p);return ret;}
il int pre(int p){
    int mid,l=1,r=p-1,k=Query(p);
    while(l<r){
        mid=(l+r)>>1;
        if(Query(mid+1)==k)r=mid;
        else l=mid+1;
    }return l;
}
il int nxt(int p){
    int mid,l=p+1,r=tot,k=Query(p+1);
    while(l<r){
        mid=(l+r)>>1;
        if(Query(mid+1)^k)r=mid;
        else l=mid+1;
    }return l;
}
bool z[maxn];
int s[maxn];ll data[maxn];
int main(){
    n=gi();
    rep(i,1,n)z[i]=gi(),s[i]=data[i]=gi();
    sort(data+1,data+n+1);
    tot=unique(data+1,data+n+1)-data-1;
    rep(i,1,n)s[i]=lower_bound(data+1,data+tot+1,s[i])-data;
    ++tot;data[0]=-1e16;
    int nowtot=0;ll ans=0;
    bool nowp;
    rep(i,1,n)
        if(nowtot==0)Appear(s[i]),nowp=z[i],nowtot=1;
        else if(nowp==z[i])Appear(s[i]),++nowtot;
        else{
            if(Query(s[i])^Query(s[i]+1))Disappear(s[i]);
            else{
                static int _pre,_nxt;static ll _p,_n;
                _pre=_nxt=0;
                if(Query(s[i]))_pre=pre(s[i]);
                if(Query(s[i]+1)^nowtot)_nxt=nxt(s[i]);
                _p=abs(data[s[i]]-data[_pre]),_n=abs(data[s[i]]-data[_nxt]);
                ans+=min(_p,_n),ans%=1000000;
                Disappear(_n<_p?_nxt:_pre);
            }
            --nowtot;
        }
    printf("%lld
",ans);
    return 0;
}
原文地址:https://www.cnblogs.com/xzz_233/p/cogs62.html