poj 4618 暴力

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=4618

#include <cstdio>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <cstring>
#include <queue>
#include <vector>
#define maxn 305
using namespace std;

vector<int> G[maxn*maxn];
int a[maxn][maxn];
int maxp; 
int N,M;

bool find(int u,int v){
    int d = G[u].size();
    for(int i=0;i<d;i++){
        if(G[u][i] == v) return true;
    }
    return false;
}
bool JudgeRowPalindrome(int x1,int y1,int x2,int y2){
       if(y1 >= y2) return true;
       if(a[x1][y1] == a[x2][y2]){
           if(find((x1)*N+y1+1,(x2)*N+y2-1))   return true;
            if(JudgeRowPalindrome(x1,y1+1,x2,y2-1)){
                G[x1*N+y1+1].push_back(x2*N+y2-1);
            return true;
            }
         }    
      else return false;
}
bool JudgeColPalindrome(int x1,int y1,int x2,int y2){
       if(x1 >= x2) return true;
       if(a[x1][y1] == a[x2][y2]){
            if(find((x1+1)*N+y1,(x2-1)*N+y2))   return true;
            
            if(JudgeColPalindrome(x1+1,y1,x2-1,y2)){
                G[(x1+1)*N+y1].push_back((x2-1)*N+y2);  
            return true;
            }
          }    
         else return false;

}
bool Judge(int x,int y,int len){ 
    for(int i=x;i<x+len;i++) 
       if(!find(N*i+y,N*i+y+len-1))  return false;
    for(int i=y;i<y+len;i++)
       if(!find(N*x+i,N*(x+len-1)+i))  return false;   
    return true;   
}
int main()
{
//    if(freopen("input.txt","r",stdin)== NULL)  {printf("Error
"); exit(0);}

    int T;
    cin>>T;
    while(T--){
        scanf("%d%d",&N,&M);
        for(int i=0;i<N;i++)
           for(int j=0;j<M;j++){
               scanf("%d",&a[i][j]);
           }
           for(int i=1;i<=N*M + N+M;i++) G[i].clear();
           
           for(int row=0;row<N;row++)
              for(int i=0;i<M;i++)
                 for(int j=i+1;j<M;j++){
                     if(find(N*row+i,N*row+j) || a[row][i] != a[row][j]) continue;
                 bool flag = JudgeRowPalindrome(row,i,row,j);
                     if(flag)   G[N*row+i].push_back(N*row+j);
                 }
          for(int col=0;col<M;col++)
              for(int i=0;i<N;i++)
                 for(int j=i+1;j<N;j++){
                     if(find(N*i+col,N*j+col) || a[i][col] != a[j][col]) continue;
                     bool flag = JudgeColPalindrome(i,col,j,col);
                     if(flag==true) G[N*i+col].push_back(N*j+col);
                 }      
        maxp = 1;
        for(int i=0;i<N;i++)
            for(int j=0;j<M;j++){
                if(N-i <= maxp || M-j <= maxp) continue;
                if(N-1-i >= M-1-j){
                    for(int k=M-1;k>=j+maxp;k--){
                        if(find(N*i+j,N*i+k)){
                            int p = k-j+1;
                            if(Judge(i,j,p)){
                                maxp = p;
                            }
                        }
                    }
                }
                else{
                    for(int k=N-1;k>=i+maxp;k--){ 
                        if(find(N*i+j,N*k+j)){
                            int p = k-i+1;
                            if(Judge(i,j,p)){
                                maxp = p;
                            }
                        }
                    }
                }
            }    
        printf("%d
",maxp);          
    }
}