bzoj2216: [Poi2011]Lightning Conductor

这题挺妙的，hzwer

#include<iostream>#include<cstdio>#include<cstring>#include<cmath>#include<cstdlib>#include<algorithm>#include<queue>using namespace std;int read(){    int x=0,f=1;char ch=getchar();    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}    return x*f;}int n;int a[500005];double f[500005],g[500005];struct data{int l,r,p;}q[500005];double cal(int j,int i){    return a[j]+sqrt(abs(i-j))-a[i];}int find(data t,int x){    int l=t.l,r=t.r;    while(l<=r)    {        int mid=(l+r)>>1;        if(cal(t.p,mid)>cal(x,mid))            l=mid+1;        else r=mid-1;    }    return l;}void dp(double *F){    int head=1,tail=0;    for(int i=1;i<=n;i++)    {        q[head].l++;        if(head<=tail&&q[head].r<q[head].l)head++;        if(head>tail||cal(i,n)>cal(q[tail].p,n))        {            while(head<=tail&&cal(q[tail].p,q[tail].l)<cal(i,q[tail].l))                tail--;            if(head>tail)                q[++tail]=(data){i,n,i};            else            {                int t=find(q[tail],i);                q[tail].r=t-1;                q[++tail]=(data){t,n,i};            }        }        F[i]=cal(q[head].p,i);    }}int main(){    n=read();    for(int i=1;i<=n;i++)a[i]=read();    dp(f);    for(int i=1;i<=n/2;i++)swap(a[i],a[n-i+1]);    dp(g);    for(int i=1;i<=n;i++)        printf("%d\n",max(0,(int)ceil(max(f[i],g[n-i+1]))));    return 0;}