P5410 【模板】扩展 KMP

P5410 【模板】扩展 KMP

 #include<bits/stdc++.h>
 using namespace std;
 const int maxn = 1e6+;
 int q, nxt[maxn], extend[maxn];
 string a, b;
 void getnxt() {
     nxt[] = b.size();
     int now = ;
     while (b[now]==b[+now] && now+<b.size()) now++;
     nxt[] = now;
     int p = ;
     for (int i = ; i < b.size(); i++) {
         if (i+nxt[i-p] < nxt[p]+p) nxt[i] = nxt[i-p];
         else {
             int now = nxt[p]+p-i;
             now = max(now,);
             while (b[now]==b[i+now] && i+now<b.size()) now++;
             nxt[i] = now;
             p = i;
         }
     }
 }
 void exkmp() {
     getnxt();
     int now = ;
     while (a[now]==b[now] && now < min(a.size(),b.size())) now++;
     extend[] = now;
     int p = ;
     for (int i = ; i < a.size(); i++) {
         if (i+nxt[i-p] < extend[p]+p) extend[i] = nxt[i-p];
         else {
             int now = extend[p]+p-i;
             now = max(now,);
             while (b[now]==a[i+now] && now<b.size() && now+i<a.size()) now++;
             extend[i] = now;
             p = i;
         }
     }
 }

 int main() {
     cin >> a >> b;
     exkmp();
     int len = b.size();
     printf("%d",nxt[]);
     for (int i = ; i < len; i++) printf(" %d",nxt[i]);
     printf("\n");

     len = a.size();
     printf("%d",extend[]);
     for (int i = ; i < len; i++) printf(" %d",extend[i]);
     printf("\n");
     return ;
 }