POJ 1743 suffix Array

Main topic

Find a continuous sequence of sub-sequences appear two times, and these two times disjoint, as long as each number in the subsequence is added/minus a number to get a new sequence, can also be considered the same

So that means the title can be converted to find two sub-sequences, the difference between each number in the two subsequence is equal

So we can ask for the difference between all the numbers 22, and then set the suffix array based on this value to solve the problem with a two-point answer.

1#include <cstdio>2#include <cstring>3#include <iostream>4 5 using namespacestd;6 Const intN =20010;7 intRank[n], sa[n], height[n];8 intWa[n], wb[n], tmp[n], wv[n];9 intA[n], b[n];Ten  One intcmpint*r,intAintBintl) A { -     returnR[A]==R[B] && r[a+l]==r[b+l]; - } the  - voidGetsa (int*r,int*sa,intNintm) - { -     inti,j,p; +     int*x=wa, *Y=WB, *T; -      for(i=0; I<m; i++) tmp[i]=0; +      for(i=0; I<n; i++) tmp[x[i]=r[i]]++; A      for(i=1; I<m; i++) tmp[i]+=tmp[i-1]; at      for(i=n-1; i>=0; i--) sa[--tmp[x[i]]]=i; -  -     //the initial p=1 is to prevent only one element from exiting the loop. -      for(p=1, j=1; P<n; j*=2, m=p) { -         //sort the Second keyword -p=0; in          for(i=n-j; i<n; i++) y[p++]=i; -          for(i=0; I<n; i++)if(SA[I]&GT;=J) y[p++]=sa[i]-J; to  +          for(i=0; I<n; i++) wv[i]=X[y[i]]; -          for(i=0; I<m; i++) tmp[i]=0; the          for(i=0; I<n; i++) tmp[wv[i]]++; *          for(i=1; I<m; i++) tmp[i]+=tmp[i-1]; $          for(i=n-1; i>=0; i--) sa[--tmp[wv[i]]]=Y[i];Panax Notoginsengt=x,x=y,y=T; -x[sa[0]]=0; the          for(p=1, i=1; I<n; i++) +X[sa[i]] = CMP (y,sa[i-1],sa[i],j)? p1:p + +; A     } the  +     return; - } $  $ voidCallheight (int*r,int*sa,intN) - { -     inti,j,k=0; the      for(i=1; I<=n; i++) rank[sa[i]]=i; - Wuyi      for(i=0; I<n; height[rank[i++]]=k) the          for(k?k--:0, j=sa[rank[i]-1] ; R[I+K]==R[J+K]; k++); -     return; Wu } -  About BOOLCheckintMintN) $ { -     intl=sa[0], r=sa[0]; -      for(intI=1; I<n; i++){ -         if(height[i]<m) { AL=sa[i], r=Sa[i]; +         } the         Else{ -L=min (sa[i], L); $R=Max (Sa[i], R); the             if(r-l>m)return true; the         } the     } the     return false; - } in  the intMain () the { About   //freopen ("a.in", "R", stdin); the     intN; the      while(SCANF ("%d", &N), N) the     { +          for(intI=0; I<n; i++) scanf ("%d", &a[i]); -          for(intI=0; i<n-1; i++) b[i]=a[i+1]-a[i]+ -; theb[n-1]=0;BayiGetsa (B,sa,n, $); theCallheight (b,sa,n-1); the  -         intL=0, R=n, ans=0; -          while(l<=R) { the             intM= (l+r) >>1; the             if(!check (m,n)) r=m-1; the             Else{ theans=m; -l=m+1; the             } the         } the         if(ans>=4) printf ("%d\n", ans+1);94         ElsePuts"0"); the     } the     return 0; the}

POJ 1743 suffix Array