Censor SCU - 4438 (KMP)

题目来源:

https://vjudge.net/contest/297070#problem/C

http://acm.scu.edu.cn/soj/problem.action?id=4438

Censor

frog is now a editor to censor so-called sensitive words (敏感词).

She has a long text pp. Her job is relatively simple -- just to find the first occurence of sensitive word ww and remove it.

frog repeats over and over again. Help her do the tedious work.

Input

The input consists of multiple tests. For each test:

The first line contains 11 string ww. The second line contains 11 string pp.

(1≤length of w,p≤5⋅1061≤length of w,p≤5⋅106, w,pw,p consists of only lowercase letter)

Output

For each test, write 11 string which denotes the censored text.

Sample Input

abc
aaabcbc
b
bbb
abc
ab

Sample Output

a
   
ab

题意:给一个模式串和一个主串,要求从主串中删除第一个模式串,然后拼接,继续删除直到不能删除输出最后的串

 比赛时候我上去就用了java但是tl(题目没给出时间空间限制)后来队友用的队列,个人感觉实现不了,最终还是没能实现,这时候我想到了KMP算法于是花了一个多小时开始琢磨板子,理解了一点改了一下,感觉没有一点问题,队友给了我半个小时,我打完之后过不了样例,我就好慌,,,赛后一看找到一个网上的ac代码和我思路一样,都是用到KMP算法思想,我一看,发现我主串和模式串好多地方搞混了QAQ...

思路:用一个数组pre记录主串中当前所指字符与模式串相匹配字符的长度。KMP思想,当主串中出现完整的模式串时,j跳到模式串pre[k-len1]的位置接着与主串i所指的下一个字符比较

参考代码:

#include
#include
#include
#include
using namespace std;
const int N=5e6+5;
char s1[N],s2[N],ans[N];
int pre[N],len1,len2,Next[N];
using namespace std;
void pre_kmp()
{
    int i=0,j=-1;
    Next[0]=-1;
    while(i

 

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