BZOJ3942 [Usaco2015 Feb]Censoring

维护一个栈。。。如果栈顶出现了要被删除的字符串就全删掉就好了，判断的话。。。kmp就行了

 /**************************************************************
     Problem: 3942
     User: rausen
     Language: C++
     Result: Accepted
     Time:224 ms
     Memory:11548 kb
 ****************************************************************/

 #include <cstdio>
 #include <cstring>

 using namespace std;
 const int N = 1e6 + ;

 char s1[N], s2[N], s[N];
 int next[N], a[N], top;

 int main() {
     int i, j, len;
     gets(s1 + ), gets(s2 + );
     len = strlen(s2 + );
     for (i = , j = next[] = ; s2[i]; ++i) {
         while (j && s2[i] != s2[j + ]) j = next[j];
         if (s2[i] == s2[j + ]) ++j;
         next[i] = j;
     }
     for (i = ; s1[i]; ++i) {
         j = a[top], s[++top] = s1[i];
         while (j && s2[j + ] != s[top]) j = next[j];
         if (s[top] == s2[j + ]) ++j;
         a[top] = j;
         if (a[top] == len) top -= len;
     }
     s[top + ] = '\0';
     puts(s + );
     return ;
 }

(p.s. AC600纪念~)