题目描述
每次写kmp都要调一万年
这题主要两个数组next[]next[]和num[]num[]
num[i]num[i]表示以ii结尾的前缀所能匹配的数量(可重叠的)
代码
#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<vector>
using namespace std;
const int L=1000010, mod=1000000007;
int n, next[L], num[L], ans;
char s[L];int main()
{cin>>n;while(n--) {ans=1;char c=getchar(); while(c < 'a' || c > 'z') c=getchar();int cnt=0; while(c >= 'a' && c <= 'z') s[++cnt]=c, c=getchar();memset(next, 0, sizeof(next)); memset(num, 0, sizeof(num));num[1]=1;for(int i=2, j=0; i<= cnt; i++){while(j && s[i] != s[j+1]) j=next[j];if(s[i] == s[j+1]) j++; next[i]=j; num[i]=num[j]+1;//printf("%d %d\n", next[i], num[i]);} for(int i=2, j=0; i <= cnt; i++){while(j && s[i] != s[j+1]) j=next[j]; if(s[i] == s[j+1]) ++j;while(j*2 > i) j=next[j]; ans=((long long)ans*(num[j]+1))%mod;}printf("%d\n", ans);}return 0;
}
