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 + 5;
 
char s1[N], s2[N], s[N];
int next[N], a[N], top;
 
int main() {
    int i, j, len;
    gets(s1 + 1), gets(s2 + 1);
    len = strlen(s2 + 1);
    for (i = 2, j = next[1] = 0; s2[i]; ++i) {
        while (j && s2[i] != s2[j + 1]) j = next[j];
        if (s2[i] == s2[j + 1]) ++j;
        next[i] = j;
    }
    for (i = 1; s1[i]; ++i) {
        j = a[top], s[++top] = s1[i];
        while (j && s2[j + 1] != s[top]) j = next[j];
        if (s[top] == s2[j + 1]) ++j;
        a[top] = j;
        if (a[top] == len) top -= len;
    }
    s[top + 1] = '';
    puts(s + 1);
    return 0;
}

 (p.s. AC600纪念~)