manacher

初始化整形数组p[1057]，整形变量ci，rei=0 //palindrome,central,right endpoint
len=INITIALIZE(s,vs);
for i=1 to len-1
   if i<rei
      p[i]=min(p[2*ci-i],rei-i)
   else p[i]=1
   while vs[i-p[i]]==vs[i+p[i]]
      p[i]=p[i]+1
   if rei<i+p[i]
      ci=i
      rei=i+p[i]
   maxlen=max(maxlen,p[i-1])
return maxlen

len=s.length
vs[0]='@'
vs[1]='!'
for j=2 i=0 to len-1
   vs[j]=s[i]
   j=j+1
   vs[j]='!'
   j=j+1
return j