poj3581 Sequence

2333

直接弃疗

第一遍搞出sa，去最小，注意sa>=3，（从1开始），后面直接输出，然后把前面剩下的复制，加到后面就好了，为什么这样呢？？ %%% http://blog.163.com/just_gogo/blog/static/1914390652011823103842787/

还有，今天是找了一个神犇的后缀数组整理做的，感觉很爽（然后一天才4个题，感觉虚死了，代码能力什么的，，，没见过的样子）

后缀数组题目：http://blog.csdn.net/libin56842/article/details/46440923

#include <cstdio>
#include <iostream>
#include <cstring>
#include<algorithm>
#define N 100005
#define inf 0x3f3f3f3f
#define LL long long
#define eps 1e-8
using namespace std;
inline int ra()
{
    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;
}

const int maxn=400005;

int a[maxn],num[maxn],n,len,ans[maxn];
int sa[2][maxn],rank[2][maxn],v[maxn];
int p=0,q=1;
int find(int x)
{
    int l=1,r=len-1;
    while (l<=r)
    {
        int mid=l+r>>1;
        if (num[mid]==x) return mid;
        else if (num[mid]>x) r=mid-1;
        else l=mid+1;
    }
}
void cal_sa(int sa[maxn], int rank[maxn], int Sa[maxn], int Rank[maxn], int k)
{
    for (int i=1; i<=n; i++) v[rank[sa[i]]]=i;
    for (int i=n; i>=1; i--) if (sa[i]>k) Sa[v[rank[sa[i]-k]]--]=sa[i]-k;
    for (int i=n-k+1; i<=n; i++) Sa[v[rank[i]]--]=i;
    for (int i=1; i<=n; i++) Rank[Sa[i]]=Rank[Sa[i-1]]+(rank[Sa[i]]!=rank[Sa[i-1]] || rank[Sa[i]+k]!=rank[Sa[i-1]+k]);
}
void work()
{
    for (int i=1; i<=n; i++) v[a[i]]++;
    for (int i=1; i<=maxn-5; i++) v[i]+=v[i-1];
    for (int i=1; i<=n; i++) sa[p][v[a[i]]--]=i;
    for (int i=1; i<=n; i++) rank[p][sa[p][i]]=rank[p][sa[p][i-1]]+(a[sa[p][i]]!=a[sa[p][i-1]]);
    for (int k=1; k<n; k<<=1,swap(p,q)) cal_sa(sa[p],rank[p],sa[q],rank[q],k);
}
void solve()
{
    work(); int pos=0;
    for (int i=1; i<=n; i++) 
        if (sa[p][i]>=3)
        {
            pos=sa[p][i]-1;
            for (int j=pos+1; j<=n; j++) printf("%d
",ans[a[j]]);
            break;
        } // while (1);
    for (int i=1; i<=pos; i++) a[i+pos]=a[i];
    n=pos*2; memset(v,0,sizeof(v)); work();
//    for (int i=1; i<=n; i++) printf("%d ",sa[p][i]); cout<<endl;
    for (int i=1; i<=n; i++) 
        if (sa[p][i]>=2 && sa[p][i]<=pos)
        {
            pos=sa[p][i]-1; //cout<<"!!"<<pos<<"!!";
            for (int j=pos+1; j<=n/2; j++) printf("%d
",ans[a[j]]);
            break;
        }
    for (int j=1; j<=pos; j++) printf("%d
",ans[a[j]]);
}
int main(int argc, char const *argv[])
{
    n=ra();
    for (int i=n; i>=1; i--) a[i]=ra(),num[i]=a[i];
    sort(num+1,num+n+1); 
    len=unique(num+1,num+n+1)-num;
    for (int i=1; i<=n; i++) ans[find(a[i])]=a[i],a[i]=find(a[i]);
    solve();
    return 0;
}