ac自动机模版

后缀数组#include <iostream>#include <cstdio>#include <cstring>using namespace std;const int maxn=200000+100;int wa[maxn], wb[maxn], wv[maxn], Ws[maxn];int Rank[maxn], height[maxn];int sa[maxn], r[maxn];char str[maxn];int cmp(int* r, int a, int b, int l){    return r[a] == r[b] && r[a + l] == r[b + l];}//将原串利用ascii码复制到r数组中，r[len]=0;//m是原串中ascii码最大值加一，合理设值，会影响通排序的基数//复杂度 nlogn//n+1//sa 是从1...n 然后sa[]是字符串下表 从0～～n//rank 是0...n，val 从1～～ rank[0]=2  代表suffix(0)在所有后缀中排第二名void da(int* r, int* sa, int n, int m){    int i, j, p, *x = wa, *y = wb, *t;    for (i = 0; i < m; i++)        Ws[i] = 0;    for (i = 0; i < n; i++)        Ws[x[i] = r[i]]++;    for (i = 1; i < m; i++)        Ws[i] += Ws[i - 1];    for (i = n - 1; i >= 0; i--)        sa[--Ws[x[i]]] = i;    for (p = 1, j = 1; p < n; j *= 2, m = p) {        for (p = 0, i = n - j; i < n; i++)            y[p++] = i;        for (i = 0; i < n; i++)            if (sa[i] >= j)                y[p++] = sa[i] - j;        for (i = 0; i < n; i++)            wv[i] = x[y[i]];        for (i = 0; i < m; i++)            Ws[i] = 0;        for (i = 0; i < n; i++)            Ws[wv[i]]++;        for (i = 1; i < m; i++)            Ws[i] += Ws[i - 1];        for (i = n - 1; i >= 0; i--)            sa[--Ws[wv[i]]] = y[i];        for (t = x, x = y, y = t, p = 1, x[sa[0]] = 0, i = 1; i < n; i++)            x[sa[i]] = cmp(y, sa[i - 1], sa[i], j) ? p - 1 : p++;    }}//n//复杂度：nlogn//height 数组下表是1...lenvoid calheight(int* r, int* sa, int n){    int i, j, k = 0;    for (i = 1; i <= n; i++)        Rank[sa[i]] = i;    for (i = 0; i < n; height[Rank[i++]] = k)        for (k ? k-- : 0, j = sa[Rank[i] - 1]; r[i + k] == r[j + k]; k++)            ;}int main(){    //freopen("in.txt", "r", stdin);    //cout<<(int)'z'<<endl;    while(scanf("%s",str)!=EOF) {        int len2=(int)(strlen(str));        str[len2]='#';        scanf("%s",str+len2+1);        int len=(int)strlen(str);        for(int i=0;i<len;i++) r[i]=str[i];        r[len]=0;        da(r, sa, len+1, 180);        calheight(r, sa, len);        int ans=0;        for(int i=2;i<len;i++) {            if(ans<height[i])                if((sa[i]<len2&&sa[i-1]>len2)||(sa[i]>len2&&sa[i-1]<len2))                    ans=height[i];        }        printf("%d\n",ans);    }    return 0;}