hdu5371 Manacher + line Tree

The problem is to find out an array string 3 equal to the first part and the 3rd part, the second part and the first part palindrome, then calculate these strings to ask such a string maximum, we first use manacher to calculate each position to the axis of symmetry to the left end of the longest palindrome radius added to the first position Palindrome radius is d[i], then he can affect the range of d[i]-i to I if he is the biggest then the answer is I-j (j for [D[i]-i,i] the number between), we can then appropriate point to add the effect of this position in the line segment tree, Then, at the end of the line tree, find out what the maximum value of this interval is.

#include <iostream>#include<algorithm>#include<cstdio>#include<string.h>#include<vector>using namespacestd;Const intmaxn=100005;intSTR[MAXN];ints[maxn*2];intrad[maxn*2];//The radius of the palindrome string centered on Iinth[maxn],to[maxn],nx[maxn],numofedg;intD[MAXN];voidADDEDG (intUintv) {     ++NUMOFEDG; To[numofedg]=v; Nx[numofedg]=h[u]; h[u]=numofedg;}voidManacher (intLen) {     intCur=1; s[0]=-1;  for(intI=0; i<len; i++) {S[cur++]=Str[i]; S[cur++]=-1; } rad[0]=1; intId=0;  for(intI=1; i<cur; i++)        {            if(rad[id]+id>i) Rad[i]=min (rad[2*id-i],rad[id]+id-i); Elserad[i]=1;  while(i-rad[i]>=0&&i+rad[i]<cur&&s[I-rad[i]] = = s[I+rad[i]) rad[i]++; if(Id+rad[i]<i+rad[i]) id=i; }      for(intI=1; i<=len; i++) {D[i]=rad[i*2]/2; if(d[i]==0)Continue; ADDEDG (i-d[i],i); }}structitree{intLoc,cl,cr,ans; intval[maxn*4]; voidBuildintLintRinto) {Val[o]=0; if(L==R)return ; intMid= (l+r) >>1; Build (L,mid,o*2); Build (Mid+1, r,o*2+1); }      voidUpdateintLintRinto) {if(l==R) {Val[o]=l;return ; }           intMid= (l+r) >>1; if(loc<=mid) Update (l,mid,o*2); ElseUpdate (mid+1, r,o*2+1); Val[o]=max (val[o*2],val[o*2+1]); }     voidQueryintLintRinto) {if(cl<=l&&r<=CR) {ans=max (Ans,val[o]);return; }         intMid= (l+r) >>1; if(cl<=mid) query (l,mid,o*2); if(cr>mid) query (mid+1, r,o*2+1); }}t;intMain () {intCAs; scanf ("%d",&CAs);  for(intCc=1; cc<=cas; Cc++)   {       intN; scanf ("%d",&N); h[0]=0; numofedg=0;  for(intI=0; i<n; i++) {H[i+1]=0; scanf ("%d",&Str[i]);       } manacher (n); intans=0; T.build (1N1); d[0]=0;  for(intI=0; i<n; i++)        {              for(intJ=h[i]; J j=Nx[j]) {T.loc=TO[J]; T.update (1N1); } t.cl=i+1; t.cr=d[i]+i; if(T.CL&GT;T.CR)Continue; T.ans=0; T.query (1N1); Ans=max (ans,t.ans-i); } printf ("Case #%d:%d\n", cc,ans*3); }    return 0;}

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hdu5371 Manacher + line Tree