#include<map>//sa
#include<set>
#include<cmath>
#include<queue>
#include<bitset>
#include<math.h>
#include<vector>
#include<string>
#include<stdio.h>
#include<cstring>
#include<iostream>
#include<algorithm>
#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
const int N=100010;
const int mod=100000000;
const int MOD1=1000000007;
const int MOD2=1000000009;
const double EPS=0.00000001;
typedef long long ll;
const ll MOD=1000000007;
const int MAX=1000000010;
const ll INF=1ll<<55;
const double pi=acos(-1.0);
typedef double db;
typedef unsigned long long ull;
char ch[5],s[N];
int w[N],sa[N],ran[N],hei[N];
int cu[N],t1[N],t2[N],str[N];
void build_sa(int n,int m) {int i,j,p,*x=t1,*y=t2;for (i=0;i<m;i++) cu[i]=0;for (i=0;i<n;i++) cu[x[i]=str[i]]++;for (i=1;i<m;i++) cu[i]+=cu[i-1];for (i=n-1;i>=0;i--) sa[--cu[x[i]]]=i;for (p=0,j=1;j<=n;m=p,p=0,j<<=1) {for (i=n-j;i<n;i++) y[p++]=i;for (i=0;i<n;i++) if (sa[i]>=j) y[p++]=sa[i]-j;for (i=0;i<m;i++) cu[i]=0;for (i=0;i<n;i++) cu[x[y[i]]]++;for (i=1;i<m;i++) cu[i]+=cu[i-1];for (i=n-1;i>=0;i--) sa[--cu[x[y[i]]]]=y[i];swap(x,y);p=1;x[sa[0]]=0;for (i=1;i<n;i++)if (y[sa[i-1]]==y[sa[i]]&&y[sa[i-1]+j]==y[sa[i]+j]) x[sa[i]]=p-1;else x[sa[i]]=p++;if (p>=n) break ;}
}
void getHeight(int n) {int i,j,k=0;for (i=0;i<=n;i++) ran[sa[i]]=i;for (i=0;i<n;i++) {if (k) k--;j=sa[ran[i]-1];while (str[i+k]==str[j+k]) k++;hei[ran[i]]=k;}
}
int main()
{int i,n,t,ca,len;ll ans;scanf("%d", &t);for (ca=1;ca<=t;ca++) {scanf("%s%s", ch, s);len=strlen(s);str[len]=0;for (i=0;i<len;i++) str[i]=s[i]-'a'+1;build_sa(len+1,30);getHeight(len);for (w[len]=len,i=len-1;i>=0;i--)if (s[i]==ch[0]) w[i]=i;else w[i]=w[i+1];for (ans=0,i=1;i<=len;i++)ans+=(ll)(len-max(sa[i]+hei[i],w[sa[i]]));printf("Case #%d: %I64d\n", ca, ans);}return 0;
}

代码：

#include<map>//sam
#include<set>
#include<cmath>
#include<queue>
#include<bitset>
#include<math.h>
#include<vector>
#include<string>
#include<stdio.h>
#include<cstring>
#include<iostream>
#include<algorithm>
#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
const int N=200010;
const int mod=100000000;
const int MOD1=1000000007;
const int MOD2=1000000009;
const double EPS=0.00000001;
typedef long long ll;
const ll MOD=1000000007;
const int MAX=2000000010;
const ll INF=1ll<<55;
const double pi=acos(-1.0);
typedef double db;
typedef unsigned long long ull;
char c[5],s[N];
int d[N*2],fa[N*2],p[N*2],dp[N*2];
int la,Now,pre[N*2],len[N*2],Son[N*2][26];
struct SAM
{void add(int x){int p=la,np=la=++Now;len[np]=len[p]+1;for(;p&&!Son[p][x];p=pre[p])Son[p][x]=np;if(!p)pre[np]=1;else{int q=Son[p][x];if(len[q]==len[p]+1)pre[np]=q;else{int nq=++Now;memcpy(Son[nq],Son[q],sizeof Son[nq]);len[nq]=len[p]+1;pre[nq]=pre[q];pre[q]=pre[np]=nq;for(;p&&Son[p][x]==q;p=pre[p])Son[p][x]=nq;}}}
}sam;
int main()
{int i,j,t,ca,Len,l,r;ll ans;scanf("%d", &t);for (ca=1;ca<=t;ca++) {scanf("%s%s", c, s);la=Now=1;Len=strlen(s);memset(pre,0,sizeof(pre));memset(len,0,sizeof(len));memset(Son,0,sizeof(Son));for (i=0;i<Len;i++) sam.add(s[i]-'a');memset(d,0,sizeof(d));memset(fa,0,sizeof(fa));for (i=1;i<=Now;i++)for (j=0;j<26;j++)if (Son[i][j]) {fa[Son[i][j]]=j,d[Son[i][j]]++;}l=1;r=1;p[1]=1;for (;l<=r;l++)for (i=0;i<26;i++)if (Son[p[l]][i]) {d[Son[p[l]][i]]--;if (d[Son[p[l]][i]]==0) p[++r]=Son[p[l]][i];}fa[1]=30;ans=0;memset(d,0,sizeof(d));memset(dp,0,sizeof(dp));for (d[1]=1,i=1;i<=r;i++)for (j=0;j<26;j++)if (Son[p[i]][j]) d[Son[p[i]][j]]+=d[p[i]];for (i=1;i<=r;i++) {if (fa[p[i]]==c[0]-'a') dp[p[i]]=d[p[i]];for (j=0;j<26;j++)if (Son[p[i]][j]) dp[Son[p[i]][j]]+=dp[p[i]];}for (i=2;i<=r;i++) ans+=(ll)dp[p[i]];printf("Case #%d: %I64d\n", ca, ans);}return 0;
}