[JSOI2008] Blue Mary's campaign map

Toot Toot

When we see N <= 50, it's fun, violence is done, but the most violent way is O (N7) ... Then add a two-point length to O (N6logn), and then we continue to optimize, the violence compared to the O (1) of the hash value, can reach O (N5logn), to barely enough ... But we can also optimize, the first matrix of all the side length of the sub-matrix of L is stored in an array, and then sort, then we enumerate the second matrix of the sub-matrix, and then in the array with Lower_bound query on the line. The complexity of this should be O (N3log (n2) * Logn).

~ ~ The hash value of a matrix is the sum of the hashes of each row ~ ~

1#include <cstdio>2#include <iostream>3#include <cmath>4#include <algorithm>5#include <cstring>6#include <cstdlib>7#include <cctype>8#include <vector>9#include <stack>Ten#include <queue> One using namespacestd; A #defineEnter puts ("") - #defineSpace Putchar (") - #defineMem (a) memset (a, 0, sizeof (a)) thetypedefLong Longll; -typedef unsignedLong Longull; -typedefDoubledb; - Const intINF =0x3f3f3f3f; + Const intEPS = 1e-8; - Const intMAXN = -; + ConstUllBase=19260817;//Please disregard A inline ll read () at { -ll ans =0; -     Charch = GetChar (), last =' '; -      while(!isdigit (CH)) {last = ch; ch =GetChar ();} -      while(IsDigit (CH)) {ans = ans *Ten+ CH-'0'; CH =GetChar ();} -     if(Last = ='-') ans =-ans; in     returnans; - } toInlinevoidWrite (ll x) + { -     if(X <0) x =-X, Putchar ('-'); the     if(x >=Ten) Write (X/Ten); *Putchar (x%Ten+'0'); $ }Panax Notoginseng  - intN, a[2][MAXN][MAXN]; theUll has[2][MAXN][MAXN]; +Ull F[MAXN], B[MAXN *MAXN]; A intCNT =0; the  +  -Ull Calc (intXintYintLBOOLflag) $ { $ull ret =0; -      for(inti = x; I <= x + L-1; ++i) ret + = Has[flag][i][y + L-1]-Has[flag][i][y-1] *F[l]; -     returnret; the } - BOOLJudgeintx)Wuyi { theCNT =0; -      for(inti =1; I <= N-x +1; ++i) Wu          for(intj =1; J <= N-x +1; ++j) -B[++CNT] = Calc (i, J, X,0); AboutSort (b +1, B + cnt +1); $      for(inti =1; I <= N-x +1; ++i) -          for(intj =1; J <= N-x +1; ++j) -         { -ull ha = Calc (i, J, X,1); A             if(*lower_bound (b +1, b +cnt +1, ha) = = ha)return 1; +         } the     return 0; - } $  the intMain () the { then =read (); the      for(intK =0; K <=1; k++) -          for(inti =1; I <= N; ++i) in              for(intj =1; J <= N; ++J) A[k][i][j] =read (); thef[0] =1; the      for(inti =1; I <= N; ++i) F[i] = f[i-1] *Base; About      for(intK =0; K <=1; ++k) the          for(inti =1; I <= N; ++i) the              for(intj =1; J <= N; ++J) Has[k][i][j] = has[k][i][j-1] *Base+A[k][i][j]; the     intL =1, R =N; +      while(L +1<R) -     { the         intMid = (L + R) >>1;Bayi         if(Judge (mid)) L =mid; the         ElseR = mid-1; the     } -Write (judge (L +1) ? L +1: L);        Enter  -     return 0; the}

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[JSOI2008] Blue Mary's campaign map