bzoj4892 [Tjoi2017]dna（SAM/SA/二分答案+Hash）

SAM

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
#define ll long long
#define inf 0x3f3f3f3f
#define N 200010
inline 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;
}
char s
;
int id['Z'],n=0,m,rt,last,mx
,son
[4],par
,ans,hh
,a
,ri
;
inline void ins(int ch){
int p=last,np=++n;last=np;mx[np]=mx[p]+1;ri[np]=1;
for(;p&&!son[p][ch];p=par[p]) son[p][ch]=np;
if(!p){par[np]=rt;return;}
int q=son[p][ch];if(mx[q]==mx[p]+1){par[np]=q;return;}
int nq=++n;memcpy(son[nq],son[q],sizeof(son[q]));
mx[nq]=mx[p]+1;par[nq]=par[q];par[q]=par[np]=nq;
for(;p&&son[p][ch]==q;p=par[p]) son[p][ch]=nq;
}
void dfs(int p,int j,int cnt){
if(j>m){ans+=ri[p];return;}
for(int i=0;i<4;++i){
if(!son[p][i]) continue;
if(id[s[j]]==i) dfs(son[p][i],j+1,cnt);
else if(cnt+1<=3) dfs(son[p][i],j+1,cnt+1);
}
}
int main(){
//  freopen("a.in","r",stdin);
int tst=read();id['A']=0;id['T']=1;id['C']=2;id['G']=3;
while(tst--){
n=0;last=rt=++n;ans=0;memset(ri,0,sizeof(ri));memset(son,0,sizeof(son));
scanf("%s",s+1);int len=strlen(s+1);
for(int i=1;i<=len;++i) ins(id[s[i]]);
memset(hh,0,sizeof(hh));
for(int i=1;i<=n;++i) hh[mx[i]]++;
for(int i=1;i<=len;++i) hh[i]+=hh[i-1];
for(int i=n;i>=1;--i) a[hh[mx[i]]--]=i;
for(int i=n;i>=1;--i){int p=a[i];ri[par[p]]+=ri[p];}
scanf("%s",s+1);m=strlen(s+1);dfs(rt,1,0);printf("%d\n",ans);
}return 0;
}

二分答案+Hash

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
#define ull unsigned long long
#define inf 0x3f3f3f3f
#define N 100010
#define k1 11117
inline 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;
}
char s1
,s2
;
ull hs1
,hs2
,bin
;
int n,m;
inline ull cal1(int l,int r){
return hs1[r]-hs1[l-1]*bin[r-l+1];
}
inline ull cal2(int l,int r){
return hs2[r]-hs2[l-1]*bin[r-l+1];
}
inline int lcp(int l1,int l2){
int l=1,r=m-l2+1;
while(l<=r){
int mid=l+r>>1;
if(cal1(l1,l1+mid-1)==cal2(l2,l2+mid-1)) l=mid+1;
else r=mid-1;
}return l-1;
}
int main(){
//  freopen("a.in","r",stdin);
int tst=read();bin[0]=1;
while(tst--){
scanf("%s",s1+1);n=strlen(s1+1);
scanf("%s",s2+1);m=strlen(s2+1);int ans=0;
for(int i=1;i<=n;++i) bin[i]=bin[i-1]*k1;
for(int i=1;i<=n;++i) hs1[i]=hs1[i-1]*k1+s1[i];
for(int i=1;i<=m;++i) hs2[i]=hs2[i-1]*k1+s2[i];
for(int i=1;i<=n;++i){
if(i+m-1>n) break;
int p1=1,p2=1;
for(int hhh=1;hhh<=4;++hhh){
int x=lcp(i+p1-1,p2);p1+=x;p2+=x;
if(hhh!=4) p1++,p2++;
if(p2>m){ans++;break;}
}
}printf("%d\n",ans);
}return 0;
}