codevs 3160

SA入门题，将2个串中间用另外的字符链接即可

调了半天一直以为是模板的错，原来是乘法超了intQAQ

 1 //#include<bits/stdc++.h>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<iostream>
 6 #include<queue>
 7 #define inc(i,l,r) for(int i=l;i<=r;i++)
 8 #define dec(i,l,r) for(int i=l;i>=r;i--)
 9 #define link(x) for(edge *j=h[x];j;j=j->next)
10 #define mem(a) memset(a,0,sizeof(a))
11 #define inf 1e9
12 #define ll long long
13 #define succ(x) (1<<x)
14 #define NM 200000+5
15 using namespace std;
16 int read(){
17     int x=0,f=1;char ch=getchar();
18     while(!isdigit(ch)){if(ch==‘-‘)f=-1;ch=getchar();}
19     while(isdigit(ch))x=x*10+ch-‘0‘,ch=getchar();
20     return x*f;
21 }
22 char s[NM];
23 int n,_t,m,rank[NM],top[NM],sa[NM],tmp[NM],h[NM],ans;
24 void getsa(){
25     m=256;int j=0;
26     inc(i,0,n)top[rank[i]=(int)s[i]]++;
27     inc(i,1,m)top[i]+=top[i-1];
28     inc(i,0,n)sa[--top[rank[i]]]=i;
29     for(int k=1;k<=n;k<<=1){
30         inc(i,0,n){
31             j=sa[i]-k;
32             if(j<0)j+=n+1;
33             tmp[top[rank[j]]++]=j;
34         }
35         sa[tmp[top[0]=0]]=j=0;
36         inc(i,1,n){
37             if(rank[tmp[i]]!=rank[tmp[i-1]]||rank[tmp[i]+k]!=rank[tmp[i-1]+k])
38             top[++j]=i;
39             sa[tmp[i]]=j;
40         }
41         memcpy(rank,sa,sizeof(sa));
42         memcpy(sa,tmp,sizeof(tmp));
43         if(j>=n)break;
44     }
45     j=0;
46     inc(i,0,n){
47         if(j)j--;
48         while(s[i+j]==s[sa[rank[i]-1]+j])j++;
49         h[rank[i]]=j;
50     }
51 }
52 int main(){
53 //    freopen("data.in","r",stdin);
54     scanf("%s",s);
55     _t=n=strlen(s);
56     s[n]=‘$‘;
57     scanf("%s",s+n+1);
58     n=strlen(s);s[n+1]=‘$‘;
59     getsa();
60     inc(i,1,n)
61     if((ll)(sa[i]-_t)*(sa[i-1]-_t)<0)ans=max(ans,h[i]);
62     printf("%d\n",ans);
63     return 0;
64 }