Censor

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

She has a long text p

. Her job is relatively simple -- just to find the first occurence of sensitive word w

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 1

string w. The second line contains 1 string p

(1≤length of w,p≤5⋅106

, w,p

consists of only lowercase letter)

Output

For each test, write 1

string which denotes the censored text.

Sample Input

    abcaaabcbcbbbbabcab

Sample Output

    aab

题意: 给你一个主串,递归删除模式串。比如: T: abc  S: aaabcbc    aaabcbc->aabc->a

非常巧妙的KMP,我们用一个栈记录当前的字符以及其在模式串匹配的位置,当位置等于模式串长度之后,将模式串长度的串出栈,从栈顶元素开始继续匹配主串.时间复杂度 O(n).

#include <stdio.h>
#include <iostream>
#include <string.h>
#include <stack>
#include <algorithm>
using namespace std;
const int N = 5000005;
struct Node{char c;int k;
};
char w[N],t[N],ans[N];
int Next[N];
void get_next(char *p){int len = strlen(p);int i=0,k=-1;Next[0] = -1;while(i<len){if(k==-1||p[i]==p[k]){i++,k++;Next[i] = k;}else k = Next[k];}
}void Kmp(char *s,char *p){int len1 = strlen(s),len2 = strlen(p);int i=0,j=0,len;stack <Node> stk;while(!stk.empty()) stk.pop();while(i<len1){if(j==-1||s[i]==p[j]){i++,j++;stk.push(Node{s[i-1],j});}else {j=Next[j];}if(j==len2){len = len2;while(!stk.empty()&&len--) stk.pop();if(stk.empty()) j = 0;else j = stk.top().k;}}int k = 0;while(!stk.empty()){ans[k++] = stk.top().c;stk.pop();}for(int i=k-1;i>=0;i--) printf("%c",ans[i]);printf("\n");
}
int main(){while(scanf("%s%s",w,t)!=EOF){get_next(w);Kmp(t,w);}return 0;
}

转载于:https://www.cnblogs.com/liyinggang/p/7403537.html

SCU 4438:Censor相关推荐

【哈希-字符串匹配+模拟栈】SCU - 4438: Censor（哈希详解哈哈哈）
写在前:由于哈希没有好好听讲,也没有下来看.这是排位我开的第一道题,直接string暴力T了.昨天其实就看了哈希,太浮躁,于是本来很简单的哈希愣是没看懂.(于是放弃去看爱5了23333333)今天补上 ...
ACM: SCU 4438 Censor - KMP
SCU 4438 Censor Time Limit:0MS Memory Limit:0KB 64bit IO Format:%lld & %llu Practice Des ...
SCU - 4438——Censor（哈希）
题目链接:http://acm.scu.edu.cn/soj/problem.action?id=4438 题意:给出一个串a和串b,串b中如果有a串则删除,删除后b剩下的串再连到一起,再找串a,反复 ...
SCU - 4438 Censor
Censor frog is now a editor to censor so-called sensitive words (敏感词). She has a long text pp. Her j ...
SCU - 4438 Censor
Censor frog is now a editor to censor so-called sensitive words (敏感词). She has a long text p . Her j ...
SCU - 4438 Censor （KMP）
Censor frog is now a editor to censor so-called sensitive words (敏感词). She has a long text pp. Her j ...
SCU 4438 Censor
$KMP$,链表. 将$p$弄成链表,每次匹配到,删掉中间的,继续匹配. #include<bits/stdc++.h> using namespace std;const int INF ...
SCU 4438 Censor (KMP)
题目大意: 就是现在给出两个字符串A, B, 长度都不超过500万, 要求每次将B中第一次A的出现删除, 然后将B剩下的两段前后合并, 然后重复这个过程直到没有可以删除的A位置, 问最后剩下的串是什么 ...
SCU 4438 Censor（Hash）题解
题意:找出字符串p中的w串删除,反复操作,直到找不到w,输出这个串思路:哈希处理前缀和,如果值相同就删掉. 代码: #include<iostream> #include<algo ...

SCU 4438:Censor