[luoguP2870] [Usaco07dec] Best bull line, Gold top Cow lines, gold (suffix array)

Portal

If the data is small, greed will be fine.

This string can be flipped back to the back, and then to find the suffix array, the rank array is very simple.

--code

1#include <cstdio>2#include <iostream>3 #defineN 600014 5 intN, len, m = the, sum;6 intBuc[n], x[n], y[n], sa[n], rank[n];7 CharS[n];8 9InlinevoidBuild_sa ()Ten { One     intI, K, p; A      for(i =0; I < m; i++) Buc[i] =0; -      for(i =0; i < Len; i++) Buc[x[i] = s[i]]++; -      for(i =1; I < m; i++) Buc[i] + = buc[i-1]; the      for(i = len-1; I >=0; i--) Sa[--buc[x[i]] =i; -      for(k =1; K <= Len; K <<=1) -     { -p =0; +          for(i = len-1; I >= len-k; i--) y[p++] =i; -          for(i =0; i < Len; i++)if(Sa[i] >= k) y[p++] = Sa[i]-K; +          for(i =0; I < m; i++) Buc[i] =0; A          for(i =0; i < Len; i++) buc[x[y[i]]]++; at          for(i =1; I < m; i++) Buc[i] + = buc[i-1]; -          for(i = len-1; I >=0; i--) sa[--buc[x[y[i] []] =Y[i]; - Std::swap (x, y); -p =1, x[sa[0]] =0; -          for(i =1; i < Len; i++) -X[sa[i]] = y[sa[i-1] [= Y[sa[i]] && y[sa[i-1] + K] = = Y[sa[i] + K]? P-1: p++; in         if(P >= Len) Break; -m =p; to     } + } -  the intMain () * { $     intI, L, R;Panax Notoginsengscanf"%d", &n); -Len = n *2; the      for(i =0; I < n; i++) GetChar (), s[i] = GetChar (), S[len-i-1] =S[i]; + Build_sa (); A      for(i =0; i < Len; i++) Rank[sa[i] =i; theL =0, R = N-1; +      while(L <=R) -     { $         if(Rank[l] <= rank[len-r-1]) Putchar (s[l++]); $         ElsePutchar (s[r--]); -         if(++sum = = the) sum =0, Putchar ('\ n'); -     } the     return 0; -}

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[luoguP2870] [Usaco07dec] Best bull line, Gold top Cow lines, gold (suffix array)