[manacher] hdu 3294 Girls' research

题意:

给一个字符x代表真实的a 然后输出的时候转换

然后就是求最长回文子串的串是什么 长度要大于1

思路:

就是裸的manacher,弄清楚下标的转换关系就好了

代码:

#include"cstdlib"
#include"cstdio"
#include"cstring"
#include"cmath"
#include"queue"
#include"algorithm"
#include"map"
#include"vector"
#include"string"
#define inf 0x7fffffff
#include"iostream"
#define ll __int64
using namespace std;
#define N 200005
char a[N],b[N*2];
int rad[N*2];
int main()
{
    char x[2];
    while(scanf("%s%s",x,&a[1])!=-1)
    {
        int maxl,maxid,id;
        int i,len;
        for(i=1; a[i]; i++)
        {
            b[i*2]=a[i];
            b[i*2+1]='#';
        }
        len=2*i;
        b[0]='?';
        b[1]='#';
        b[len]='';
        maxid=id=0;
        maxl=0;
        int ansi;
        for(i=1; i<len; i++)
        {
            if(maxid>i)  rad[i]=min(rad[2*id-i],maxid-i);
            else  rad[i]=1;
            while(b[i-rad[i]]==b[i+rad[i]])
            {
                rad[i]++;
            }
            if(rad[i]+i>maxid)
            {
                maxid=rad[i]+i;
                id=i;
            }
            if(rad[i]>maxl)
            {
                maxl=rad[i];
                ansi=i;
            }
        }
        if(maxl-1<2) puts("No solution!");
        else
        {
            int kk=x[0]-'a';
            int ans=maxl-1,ansl,ansr;
            ansl=(ansi-(ans-1))/2-1;
            ansr=ansl+ans-1;
            printf("%d %d
",ansl,ansr);
            for(int i=ansl; i<=ansr; i++)
            {
                if(a[i+1]-kk<'a') printf("%c",'z'+1-'a'+(a[i+1]-kk));
                else printf("%c",a[i+1]-kk);
            }
            puts("");
        }
    }
    return 0;
}


原文地址:https://www.cnblogs.com/bhlsheji/p/5322042.html