扩展KMP详细解释见 链接
方法一：KMP
//#include <bits/stdc++.h>
#include<stdio.h>
#include<string.h>
#include<string>
#include<math.h>
#include<algorithm>
#include<iostream>
#include<queue>
#include<vector>
#include<stack>
#include<map>
#include<set>
#include<stdlib.h>
#include<time.h>
#include <iomanip>
#define lowbit(x) (x&(-x))
#define inf 0x7fffffff
#define linf 0x7fffffffffffffff
#define fil(x,y) memset(x,y,sizeof(x))
#define fup(i,x,y) for(int i=(x);i<=(y);i++)
#define fdn(i,x,y) for(int i=(x);i>=(y);i--)
#define sp(x) setprecision(x)
#define sd(n) scanf("%d",&n)
#define sdd(n,m) scanf("%d%d",&n,&m)
#define sddd(n,m,k) scanf("%d%d%d",&n,&m,&k)
#define sld(n) scanf("%lld",&n)
#define sldd(n,m) scanf("%lld%lld",&n,&m)
#define slddd(n,m,k) scanf("%lld%lld%lld",&n,&m,&k)
#define sf(n) scanf("%lf",&n)
#define sff(n,m) scanf("%lf%lf",&n,&m)
#define sfff(n,m,k) scanf("%lf%lf%lf",&n,&m,&k)
#define sc(n) scanf("%s",n)
#define pf(x) printf("%d\n",x)
#define pfl(x) printf("%lld\n",x)
#define pff(x) printf("%lf\n",x)
#define debug printf("!!\n");
#define N 4000*102
#define M 4000009
#define pi acos(-1)
#define eps 1e-2
//cout.setf(ios::fixed);
//freopen("out.txt","w",stdout);// freopen("in.txt","r",stdin);
using namespace std;
typedef long long ll;
typedef double db;
const int mod=1e9+7;
char c[1000005],s[1000005];
int ne[1000005],ans,len1,len2;
void ini()
{
ne[0]=-1;
int k=-1;
fup(i,1,len1-1)
{
while(k>-1&&c[k+1]!=c[i]) k=ne[k];
if(c[k+1]==c[i]) k++;
ne[i]=k;
}
}
void kmp()
{
int k=-1;
fup(i,0,len2-1)
{
while(k>-1&&c[k+1]!=s[i]) k=ne[k];
if(c[k+1]==s[i]) k++;
}
if(k==-1) puts("0");
else
{
c[k+1]='\0';
printf("%s %d\n",c,k+1);
}
}
void solve()
{
while(~scanf("%s%s", c, s))
{
len1=strlen(c);
len2=strlen(s);
ans=0;
ini();
kmp();
}
}
int main()
{
int tt=1,k=1;
// sd(tt);
// getchar();
while(tt--)
{
solve();
}
return 0;
}
方法二：扩展KMP
//#include <bits/stdc++.h>
#include<stdio.h>
#include<string.h>
#include<string>
#include<math.h>
#include<algorithm>
#include<iostream>
#include<queue>
#include<vector>
#include<stack>
#include<map>
#include<set>
#include<stdlib.h>
#include<time.h>
#include <iomanip>
#define lowbit(x) (x&(-x))
#define inf 0x7fffffff
#define linf 0x7fffffffffffffff
#define fil(x,y) memset(x,y,sizeof(x))
#define fup(i,x,y) for(int i=(x);i<=(y);i++)
#define fdn(i,x,y) for(int i=(x);i>=(y);i--)
#define sp(x) setprecision(x)
#define sd(n) scanf("%d",&n)
#define sdd(n,m) scanf("%d%d",&n,&m)
#define sddd(n,m,k) scanf("%d%d%d",&n,&m,&k)
#define sld(n) scanf("%lld",&n)
#define sldd(n,m) scanf("%lld%lld",&n,&m)
#define slddd(n,m,k) scanf("%lld%lld%lld",&n,&m,&k)
#define sf(n) scanf("%lf",&n)
#define sff(n,m) scanf("%lf%lf",&n,&m)
#define sfff(n,m,k) scanf("%lf%lf%lf",&n,&m,&k)
#define sc(n) scanf("%s",n)
#define pf(x) printf("%d\n",x)
#define pfl(x) printf("%lld\n",x)
#define pff(x) printf("%lf\n",x)
#define debug printf("!!\n");
#define N 4000*102
#define M 4000009
#define pi acos(-1)
#define eps 1e-2
//cout.setf(ios::fixed);
//freopen("out.txt","w",stdout);// freopen("in.txt","r",stdin);
using namespace std;
typedef long long ll;
typedef double db;
const int mod=1e9+7;
char c[1000005],s[1000005];
int ne[1000005],ex[1000005],ans;
void ini(char *str)
{
int len=strlen(str);
ne[0]=len;
int k=0;
while(str[k]==str[k+1]&&k+1<len) k++;
ne[1]=k;
int po=1;
fup(i,2,len-1)
{
if(ne[i-po]+i<ne[po]+po) ne[i]=ne[i-po];
else
{
int j=ne[po]+po-i;
if(j<0) j=0;
while(i+j<len&&str[j]==str[j+i]) j++;
ne[i]=j;
po=i;
}
}
}
void exkmp(char *s1,char *s2)
{
int len1=strlen(s1),len2=strlen(s2);
int k=0;
ini(s2);
while(s1[k]==s2[k]&&k<min(len1,len2)) k++;
ex[0]=k;
int po=0;
fup(i,1,len1-1)
{
if(ne[i-po]+i<ex[po]+po) ex[i]=ne[i-po];
else
{
int j=ex[po]+po-i;
if(j<0) j=0;
while(i+j<len1&&j<len2&&s2[j]==s1[j+i]) j++;
ex[i]=j;
po=i;
}
}
}
void solve()
{
while(~sc(c))
{
sc(s);
exkmp(s,c);
int n=strlen(s);
int flag=0;
fup(i,0,n-1)
{
if(ex[i]==n-i)
{
flag=1;
printf("%s %d\n",s+i,n-i);
break;
}
}
if(!flag) puts("0");
}
}
int main()
{
int tt=1,k=1;
// sd(tt);
// getchar();
while(tt--)
{
solve();
}
return 0;
}