动物园「NOI2014」

题意

求不相交前后缀匹配数量。

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思路

注意本题求的是数量，不是长度。

代码

#include <bits/stdc++.h>

using namespace std;

namespace StandardIO {

	template<typename T> inline void read (T &x) {
		x=0;T f=1;char c=getchar();
		for (; c<'0'||c>'9'; c=getchar()) if (c=='-') f=-1;
		for (; c>='0'&&c<='9'; c=getchar()) x=x*10+c-'0';
		x*=f;
	}
	template<typename T> inline void write (T x) {
		if (x<0) putchar('-');
		if (x>=10) write(x/10);
		putchar(x%10+'0');
	}

}

using namespace StandardIO;

namespace Solve {
	
	const int N=1000100;
	const int MOD=1000000007;
	
	int n,m,ans;
	char s[N];
	int next[N],num[N];

	inline void MAIN () {
		read(n);
		while (n--) {
			scanf("%s",s+1),m=strlen(s+1),ans=1,num[1]=1;
			for (register int i=2,j=0; i<=m; ++i) {
				while (j&&s[j+1]!=s[i]) j=next[j];
				if (s[j+1]==s[i]) ++j;
				next[i]=j,num[i]=num[j]+1;
			}
			for (register int i=1,j=0; i<=m; ++i) {
				while (j&&s[j+1]!=s[i]) j=next[j];
				if (s[j+1]==s[i]) ++j;
				while (j>i/2) j=next[j];
				ans=(1ll*ans*(num[j]+1))%MOD;
			}
			write(ans),putchar('\n');
		}
	}

}

int main () {
//	freopen(".in","r",stdin);
//	freopen(".out","w",stdout);
	Solve::MAIN();
}