KMP

No.1 (序列) 

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#include<bit/stdc++.h>
using namespace std;
int a[1000020];
int r[1000020];
int b[1000020];
int s[1000020];
int Next[1000020];
void get(int *p,int l)
{
    int i = 0, j = -1;
    Next[i] = j;
    while(i < l)
    {
        while( j != -1 && s[i] != s[j])
            j =Next[j];
        Next[++i] = ++j;
    }
}
int kmp(int n,int m)//kmp匹配
{
    get(b,m);
    int i = 0, j = 0;
    int ans = 0;
    while(i < n){
        while( j != -1 && s[j] != r[i])
            j = Next[j];
        i++,j++;
        if(j == m-1) ans++;
    }
    return ans;
}
int main()
{
    int n,m,t;
    cin>>n>>m;
    for(int i=0;i<n;i++)
    {
        cin>>a[i];
        if(i)r[i-1]=a[i]-a[i-1];//把输入转换为每一项与前一项的差值
    }
    for(int i=0;i<m;i++)
    {
        cin>>b[i];
        if(i)s[i-1]=b[i]-b[i-1];//同上
    }
    cout<<kmp(n,m)<<endl;
    return 0;
}
No.2 (递归输出后缀长度) 
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#include<bit/stdc++.h>
using namespace std;
int Next[400020];
void get(string s)
{
    int i=0,j=-1;
    Next[i]=j;
    while(i<s.length())
    {
        if(j==-1||s[i]==s[j])
            Next[++i]=++j;
        else j=Next[j];
    }
}
void print(int n)
{
    if(n==0)return;
    print(Next[n]);
    cout<<n<<' ';
}
int main()
{

    string s;
    while(cin>>s)
    {
        get(s);
        print(Next[s.length()]);
        cout<<s.length()<<endl;
    }
    return 0;
}