JZOJ5437. 【NOIP2017提高A组集训10.31】Sequence

题目

题解

code

#include<queue>
#include<cstdio>
#include<iostream>
#include<algorithm>
#include <cstring>
#include <string.h>
#include <cmath>
#include <math.h>
#define ll long long
#define N 1000003
#define db double
#define P putchar
#define G getchar
#define mo 1000000007
using namespace std;
char ch;
void read(int &n)
{
n=0;
ch=G();
while((ch<'0' || ch>'9') && ch!='-')ch=G();
ll w=1;
if(ch=='-')w=-1,ch=G();
while('0'<=ch && ch<='9')n=(n<<3)+(n<<1)+ch-'0',ch=G();
n*=w;
}

int max(int a,int b){return a>b?a:b;}
ll min(ll a,ll b){return a<b?a:b;}
ll abs(ll x){return x<0?-x:x;}
ll sqr(ll x){return x*x;}
void write(ll x){if(x>9) write(x/10);P(x%10+'0');}
void writeln(ll x){write(x);P('\n');}
int gcd(int x,int y){return y==0?x:gcd(y,x%y);}

int nxt
,a
,b
,n,m,ans;

void make(int* t,int len)
{
memset(nxt,0,sizeof(nxt));
int j=0;
for(int i=2;i<=len;i++)
{
while(j>0 && t[j+1]!=t[i])j=nxt[j];
if(t[i]==t[j+1])j++;
nxt[i]=j;
}
}

int kmp(int l)
{
int j=0,sum=0;
for(int i=1;i<n;i++)
{
while(j>0 && a[i]!=b[j+1])j=nxt[j];
if(a[i]==b[j+1])j++;
if(j==l)
{
sum++;
j=nxt[l];
}
}
return sum;
}

int main()
{
freopen("sequence.in","r",stdin);
freopen("sequence.out","w",stdout);
read(n);read(m);
for(int i=1;i<=n;i++)
read(a[i]),a[i-1]=a[i]-a[i-1];
for(int i=1;i<=m;i++)
read(b[i]),b[i-1]=b[i]-b[i-1];
make(b,m-1);
writeln(kmp(m-1));
}