hdu-6153 A Secret

来源：互联网发布：ae2018cc破解版mac 编辑：程序博客网时间：2024/06/04 18:00

先翻转数组，然后用套kmp模板

#include"cstdio"#include"cstring"#include"iostream"#include"algorithm"typedef long long LL;const LL mod = 1e9+7;using namespace std;const int maxn = 1e6+9;char s[maxn],t[maxn];int nxt[maxn];int n,m;LL ans;void build(char *str){    nxt[0] = -1;    int k = -1, j = 0;    while(j < m){        while(k!=-1 && str[k] != str[j]) k = nxt[k];        nxt[++j] = ++k;    }}void work(){    ans = 0;    LL j = 0;    int cnt = 0;    for(int i = 0; i <= n; i++){        while(j != -1 && s[i] != t[j]){            ans = (ans + (j+1)*j/2)%mod;            j = nxt[j];        }        ++j;        if(j >= m){            cnt++;            ans = (ans+(j+1)*j/2)%mod;            j = nxt[j];        }    }}int main(){    int T;    scanf("%d",&T);    while(T--){        scanf("%s%s",s,t);        n = strlen(s);        m = strlen(t);        reverse(s,s+n); reverse(t,t+m);        build(t);        work();        cout<<ans<<endl;    }    return 0;}

阅读全文

0 0