HDU 4644 Bwt (KMP)

After reading the question, you can easily think of how to restore the given array to the original array.

After the original array is restored, both the AC automatic machine and KMP can be solved-although I think KMP will time out.

So how to restore this string is a difficult question...

GC $ aaac

1234567

Changed

$ Aaaccg

3456271

Then you follow the sorted subscript.

Will find

$-> A-> C-> G

3 5 2 4 6 7

The original string is restored.

#include <cstdio>#include <iostream>#include <cstring>#include <algorithm>#define maxn 100186using namespace std;struct node{    char ch;    int index;    bool operator < (const node & cmp)const    {        return ch<cmp.ch;    }}save[maxn];char t[maxn];char str[maxn],txt[maxn];int next[maxn];void getnext(int len){    next[0]=0;next[1]=0;    for(int i=1;i<len;i++)    {        int j=next[i];        while(j && txt[j]!=txt[i])j=next[j];        next[i+1]=txt[j]==txt[i]?j+1:0;    }}void find(int n,int m){    int j=0;    for(int i=0;i<n;i++)    {        while(j&&txt[j]!=str[i])j=next[j];        if(txt[j]==str[i])j++;        if(j==m){printf("YES\n");return ;}    }    printf("NO\n");}int main(){    while(scanf("%s",t)!=EOF)    {        int len=strlen(t);        for(int i=0;i<len;i++)        {            save[i].ch=t[i];            save[i].index=i;        }        stable_sort(save,save+len);        int now=save[0].index;        for(int i=0;i<len-1;i++)        {            str[i]=save[now].ch;            now=save[now].index;        }        int q;        scanf("%d",&q);        while(q--)        {            scanf("%s",txt);            int m=strlen(txt);            getnext(m);            find(len-1,m);        }    }    return 0;}