cogs1533 [HNOI2002]营业额统计

cogs1533 [HNOI2002]营业额统计

---

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

和上一篇博文完全一样2333

另外：goto语句只要不乱用还是挺好用的

// 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;
const int maxn=(1<<15)+4;
int n;
//BIT begin
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;}
//BIT end.
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;
}
int s[maxn];ll data[maxn];
bool yes[maxn];
int main(){
    scanf("%d",&n);
    rep(i,1,n){
        if(scanf("%d",&s[i])^1)s[i]=0;
        data[i]=s[i];
    }
    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;
    ll ans=data[s[1]];
    data[0]=-1e14;
    ++tot;
    Appear(s[1]);yes[s[1]]=1;
    rep(i,2,n){
        static int a,b;
        a=b=0;
        if(yes[s[i]])goto end;
        yes[s[i]]=1;
        if(Query(s[i]))a=pre(s[i]);
        if(Query(s[i])^(i-1))b=nxt(s[i]);
        ans+=min(abs(data[a]-data[s[i]]),abs(data[b]-data[s[i]]));
        end:Appear(s[i]);
    }
    printf("%lld\n",ans);
    return 0;
}