2017.3.4[hihocoder#1407]后缀数组二·重复旋律2

重复旋律大礼包

http://hihocoder.com/problemset/problem/1407

#include<cmath>
#include<queue>
#include<cstdio>
#include<vector>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define N 100010
#define RG register
#define inf 0x3f3f3f3f
#define Inf 99999999999999999LL
using namespace std;
typedef long long LL;
int l=1,n,r,ans,a[N],b[N],sa[N],num[N],ssa[N],cnta[N],cntb[N],heit[N],order[N];
inline int Abs(RG const int &a){return a>0?a:-a;}
inline int Max(RG const int &a,RG const int &b){return a>b?a:b;}
inline int Min(RG const int &a,RG const int &b){return a>b?b:a;}
inline int gi(){
    RG int x=0;RG bool flag=0;RG char c=getchar();
    while((c<'0'||c>'9')&&c!='-') c=getchar();
    if(c=='-') c=getchar(),flag=1;
    while(c>='0'&&c<='9') x=x*10+c-'0',c=getchar();
    return flag?-x:x;
}
inline void getsa(){
    for (RG int i=1;i<=n;++i)    ++cnta[num[i]];
    for (RG int i=1;i<=1000;++i) cnta[i]+=cnta[i-1];
    for (RG int i=n;i;--i)       sa[cnta[num[i]]--]=i;
    order[sa[1]]=1;
    //cout<<"sdmo"<<endl;
    if(n>1){
    for (RG int i=2;i<=n;++i){
        order[sa[i]]=order[sa[i-1]];
        if(num[sa[i]]!=num[sa[i-1]]) ++order[sa[i]];
    }
    //cout<<"cdsamoc"<<endl;
        for (RG int now=1;order[sa[n]]<n;now<<=1){
        memset(cnta,0,sizeof(cnta));
        memset(cntb,0,sizeof(cntb));
        for (RG int i=1;i<=n;++i){
            ++cnta[a[i]=order[i]];
            ++cntb[b[i]=(i+now<=n)?order[i+now]:0];
        }
        for (RG int i=1;i<=n;++i) cntb[i]+=cntb[i-1];
        for (RG int i=n;i;--i)    ssa[cntb[b[i]]--]=i;
        for (RG int i=1;i<=n;++i) cnta[i]+=cnta[i-1];
        for (RG int i=n;i;--i)    sa[cnta[a[ssa[i]]]--]=ssa[i];
        order[sa[1]]=1;
        for (RG int i=2;i<=n;++i){
        order[sa[i]]=order[sa[i-1]];
        if(a[sa[i]]!=a[sa[i-1]]||b[sa[i]]!=b[sa[i-1]]) ++order[sa[i]];
        }
    }
    //cout<<"dsji"<<endl;
    }
    for (RG int i=1,j=0;i<=n;++i){
    if(j) --j;
    while(num[i+j]==num[sa[order[i]-1]+j]) ++j;
    heit[order[i]]=j;
    }
}
inline bool check(RG int mid){
    RG int maxn,minn=inf;
    for (RG int i=1;i<=n;++i)
    if(heit[i]<mid)
        maxn=minn=sa[i];
    else{
        maxn=Max(maxn,sa[i]);
        minn=Min(minn,sa[i]);
        if(maxn-minn>=mid) return 1;
    }
    return 0;
}
inline void work(){
    n=gi();r=n;
    for (RG int i=1;i<=n;++i) num[i]=gi();
    //cout<<"cesj"<<endl;
    getsa();
    //cout<<"feanfila"<<endl;
    while(l<=r){
    RG int mid=(l+r)>>1;
    if(check(mid)) ans=mid,l=mid+1;
    else           r=mid-1;
    }
    printf("%d
",ans);
}
int main(){
    work();
    return 0;
}