Lưu ý: Các code mẫu dưới đây chỉ mang tính tham khảo và có thể không AC được bài tập này

Code mẫu của flashmt

const fi='';
      fo='';
      maxn=505;
var n,m,re,x,y:longint;
    a:array[0..maxn,0..maxn] of char;
    vv,v,p,q,r,s:array[0..maxn,0..maxn] of longint;

function min(a,b:longint):longint;
begin
     if a<=b then min:=a else min:=b;
end;

procedure pr;
var i,j,t:longint; c:char;
begin
     assign(input,fi);
     reset(input);
     readln(m,n);
     for i:=1 to m do
     begin
          for j:=1 to n do
          begin
               read(a[i,j]);
               if a[i,j]=a[i-1,j] then v[i,j]:=v[i-1,j]+1 else v[i,j]:=0;
               if a[i,j]=a[i,j-1] then p[i,j]:=min(p[i,j-1]+1,v[i,j])
               else p[i,j]:=0;
          end; 
          readln;
          for j:=n downto 1 do
              if a[i,j]=a[i,j+1] then r[i,j]:=min(r[i,j+1]+1,v[i,j])
              else r[i,j]:=0;
     end;
     x:=0; y:=0; re:=-1;
     for i:=m downto 1 do
     begin
          for j:=n downto 1 do
          begin
               if a[i,j]=a[i+1,j] then vv[i,j]:=vv[i+1,j]+1 else vv[i,j]:=0;
               if a[i,j]=a[i,j+1] then q[i,j]:=min(q[i,j+1]+1,vv[i,j])
               else q[i,j]:=0;
          end;
          for j:=1 to n do
          begin
              if a[i,j]=a[i,j-1] then s[i,j]:=min(s[i,j-1]+1,vv[i,j])
              else s[i,j]:=0;
              t:=min(min(p[i,j],q[i,j]),min(r[i,j],s[i,j]));
              if t>=re then
              begin
                   if (t>re) or (i<x) or ((i=x) and (j<y)) then
                   begin
                   re:=t; x:=i; y:=j;
                   end;
              end;
          end;
     end;
     close(input);
end;

procedure wf;
begin
     assign(output,fo);
     rewrite(output);
     write(x,' ',y,' ',re);
     close(output);
end;

begin
     pr;
     wf;
end.

Code mẫu của ladpro98

program DIAMOND;
uses    math;
const   maxn=505;
        fi='';
var     a:array[0..maxn,0..maxn] of char;
        f1,f2,f3,f4:array[0..maxn,0..maxn] of longint;
        res,n,m,x,y:longint;

procedure input;
var     inp:text;
        i,j:longint;
begin
        assign(inp,fi);reset(inp);
        readln(inp,m,n);
        for i:=1 to m do begin
                for j:=1 to n do read(inp,a[i,j]);
                readln(inp);
        end;
        close(inp);
end;

procedure dp;
var     i,j,temp:longint;
begin
        for i:=1 to M do
        for j:=1 to n do
        begin
                if (a[i-1,j]<>a[i,j]) or (a[i,j-1]<>a[i,j]) then f1[i,j]:=1
                else
                f1[i,j]:=min(f1[i-1,j],f1[i,j-1])+1;
        end;
        for i:=1 to M do
        for j:=n downto 1 do
        begin
                if (a[i-1,j]<>a[i,j]) or (a[i,j+1]<>a[i,j]) then f2[i,j]:=1
                else
                f2[i,j]:=min(f2[i-1,j],f2[i,j+1])+1;
        end;
        for i:=M downto 1 do
        for j:=1 to n do
        begin
                if (a[i+1,j]<>a[i,j]) or (a[i,j-1]<>a[i,j]) then f3[i,j]:=1
                else
                f3[i,j]:=min(f3[i+1,j],f3[i,j-1])+1;
        end;
        for i:=M downto 1 do
        for j:=n downto 1 do
        begin
                if (a[i+1,j]<>a[i,j]) or (a[i,j+1]<>a[i,j]) then f4[i,j]:=1
                else
                f4[i,j]:=min(f4[i+1,j],f4[i,j+1])+1;
        end;
        for i:=1 to M do
        for j:=1 to n do
        begin
                temp:=min(
                min(f1[i,j],f2[i,j]),
                min(f3[i,j],f4[i,j]));
                if res<temp then begin
                        res:=temp;
                        x:=i;
                        y:=j;
                end;
        end;
end;

begin
        input;
        dp;
        write(x,' ',y,' ',res-1);
end.

Code mẫu của RR

uses math;
const
  FINP      =   '';
  FOUT          =       '';
  MAXN          =       555;

var
  f1,f2         :       text;
  m,n           :       longint;
  a             :       array[-1..MAXN,-1..MAXN] of char;
  d1,d2,d3,d4   :       array[-1..MAXN,-1..MAXN] of longint;

procedure openF;
    begin
      assign(f1,FINP); reset(f1);
      assign(f2,FOUT); rewrite(f2);
    end;

procedure closeF;
    begin
      close(f1);
      close(f2);
    end;

procedure inp;
    var
      i,j:longint;
    begin
      readln(f1,m,n);
      for i:=1 to m do
        begin
          for j:=1 to n do read(f1,a[i,j]);
          readln(f1);
        end;
    end;

procedure solve;
    var
      now,i,j,res,li,lj:longint;
    begin
      for i:=1 to m do
        begin
          for j:=1 to n do
            if (a[i,j]=a[i-1,j]) and (a[i,j]=a[i,j-1]) then
              d1[i,j]:=min(d1[i-1,j],d1[i,j-1])+1
            else d1[i,j]:=1;

          for j:=n downto 1 do
            if (a[i,j]=a[i-1,j]) and (a[i,j]=a[i,j+1]) then
              d2[i,j]:=min(d2[i-1,j],d2[i,j+1])+1
            else d2[i,j]:=1;
        end;

      for i:=m downto 1 do
        begin
          for j:=1 to n do
            if (a[i,j]=a[i+1,j]) and (a[i,j]=a[i,j-1]) then
              d3[i,j]:=min(d3[i+1,j],d3[i,j-1])+1
            else d3[i,j]:=1;

          for j:=n downto 1 do
            if (a[i,j]=a[i+1,j]) and (a[i,j]=a[i,j+1]) then
              d4[i,j]:=min(d4[i+1,j],d4[i,j+1])+1
            else d4[i,j]:=1;
        end;

      res:=0;
      for i:=1 to m do
      for j:=1 to n do
        begin
          now:=min(min(d1[i,j],d2[i,j]),min(d3[i,j],d4[i,j]));
          if now>res then
            begin
              res:=now;
              li:=i; lj:=j;
            end;
        end;
      writeln(f2,li,' ',lj,' ',res-1);
    end;

begin
  openF;
  inp;
  solve;
  closeF;
end.

Code mẫu của hieult

#include <set>
#include <map>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <cctype>
#include <cstdio>
#include <string>
#include <vector>
#include <cassert>
#include <cstdlib>
#include <cstring>
#include <sstream>
#include <iomanip>
#include <iostream>
#include <algorithm>

using namespace std;

typedef long long ll;
//typedef long double ld;
typedef double ld;
typedef unsigned int ui;
typedef unsigned long long ull;

#define Rep(i,n) for(__typeof(n) i = 0; i < (n); ++i)
#define Repd(i,n) for(__typeof(n) i = (n)-1; i >= 0; --i)
#define For(i,a,b) for(__typeof(b) i = (a); i <= (b); ++i)
#define Ford(i,a,b) for(__typeof(a) i = (a); i >= (b); --i)
#define Fit(i,v) for(__typeof((v).begin()) i = (v).begin(); i != (v).end(); ++i)
#define Fitd(i,v) for(__typeof((v).rbegin()) i = (v).rbegin(); i != (v).rend(); ++i)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define sz(a) ((int)(a).size())
#define all(a) (a).begin(), (a).end()
#define ms(a,x) memset(a, x, sizeof(a))
#define nl puts("")
#define sp printf(" ")
#define ok puts("ok")
//#include <conio.h>

template<class F, class T> T convert(F a, int p = -1) { stringstream ss; if (p >= 0) ss << fixed << setprecision(p); ss << a; T r; ss >> r; return r; }
template<class T> void db(T a, int p = -1) { if (p >= 0) cout << fixed << setprecision(p); cout << a << " "; }
template<class T> T gcd(T a, T b) { T r; while (b != 0) { r = a % b; a = b; b = r; } return a; }
template<class T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
template<class T> T sqr(T x) { return x * x; }
template<class T> T cube(T x) { return x * x * x; }
template<class T> struct Triple { T x, y, z; Triple() {} Triple(T _x, T _y, T _z) : x(_x), y(_y), z(_z) {} };
template<class T> Triple<T> euclid(T a, T b) { if (b == 0) return Triple<T>(1, 0, a); Triple<T> r = euclid(b, a % b); return Triple<T>(r.y, r.x - a / b * r.y, r.z); }
template<class T> int getbit(T s, int i) { return (s >> i) & 1; }
template<class T> T onbit(T s, int i) { return s | (T(1) << i); }
template<class T> T offbit(T s, int i) { return s & (~(T(1) << i)); }
template<class T> int cntbit(T s) { return s == 0 ? 0 : cntbit(s >> 1) + (s & 1); }
const int bfsz = 1 << 16; char bf[bfsz + 5]; int rsz = 0;int ptr = 0;
char gc() { if (rsz <= 0) { ptr = 0; rsz = fread(bf, 1, bfsz, stdin); if (rsz <= 0) return EOF; } --rsz; return bf[ptr++]; }
void ga(char &c) { c = EOF; while (!isalpha(c)) c = gc(); }
int gs(char s[]) { int l = 0; char c = gc(); while (isspace(c)) c = gc(); while (c != EOF && !isspace(c)) { s[l++] = c; c = gc(); } s[l] = '\0'; return l; }
template<class T> bool gi(T &v) {
    v = 0; char c = gc(); while (c != EOF && c != '-' && !isdigit(c)) c = gc(); if (c == EOF) return false; bool neg = c == '-'; if (neg) c = gc();
    while (isdigit(c)) { v = v * 10 + c - '0'; c = gc(); } if (neg) v = -v; return true;
}

const double PI = 2 * acos(0);
const string months[] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
const int days[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int dr[] = {0, 0, -1, +1};
const int dc[] = {-1, +1, 0, 0};
const int inf = (int)1e9 + 5;
const ll linf = (ll)1e16 + 5;
const double eps = ld(1e-9);
const ll mod = 100000007;
typedef pair<int, int> II;

#define maxn 505
#define maxv 1005

int x[maxn][maxn], u[maxn][maxn];
char s[maxn];
int n, m;

vector<vector<int> > cal(int a[][maxn]){
    vector<vector<int> > res;
    res.resize(n);
    Rep(i, n) res[i].resize(m);
    int t;
    Rep(i, n) Rep(j, m){
        if(i == 0 || j == 0){ res[i][j] = 1; continue;}
        if(a[i][j] != a[i - 1][j] || a[i][j] != a[i][j - 1]) { res[i][j] = 1; continue;}
        if(res[i][j - 1] <= res[i - 1][j]){
            t = res[i][j - 1];
            res[i][j] = t - 1;
            if(a[i][j + t - 1] == a[i][j]){
                res[i][j] = t;
                if(a[i][j + t] == a[i][j])
                    res[i][j] = t + 1;
            }
        }

        else{
            t = res[i - 1][j];
            res[i][j] = t;
            if(a[i][j + t] == a[i][j]) res[i][j] = t + 1;
        }
    }
    return res;
}

int main(){
//    freopen("in.txt", "r", stdin);
//    freopen("out.txt", "w", stdout);

    gi(n); gi(m);
    ms(x, -1); ms(u, -1);
    Rep(i, n){
        gs(s);
        Rep(j, m){ 
            x[i][j] = s[j] - 'A';
            u[n - i - 1][m - j - 1] = x[i][j];
        }
    }

    vector<vector<int> > V1 = cal(x), V2 = cal(u);
    int res = 0, temp;
    II kq;
    Rep(i, n) Rep(j, m) {
        temp = min(V1[i][j], V2[n - 1 - i][m - 1 - j]);
        if(res < temp){
            res = temp;
            kq = mp(i, j);
        }
    }
    cout << kq.fi + 1<< " " << kq.se + 1<< " " << res - 1;

    return 0;
}

Code mẫu của ll931110

#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstring>
#include <ctime>
#include <deque>
#include <fstream>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
using namespace std;

char a[505][505];
int m,n;
int UL[505][505],UR[505][505],BL[505][505],BR[505][505];

int main()
{
//    freopen("joker.in","r",stdin);
//    freopen("joker.ou","w",stdout);
    scanf("%d %d", &m, &n);
    for (int i = 1; i <= m; i++)
      for (int j = 1; j <= n; j++)
        while (1)
        {
            scanf("%c", &a[i][j]);  if ('A' <= a[i][j] && a[i][j] <= 'Z') break;
        }
    for (int i = 1; i <= m; i++)
      for (int j = 1; j <= n; j++) 
        UL[i][j] = (a[i][j] != a[i - 1][j] || a[i][j] != a[i][j - 1]) ? 0 : (1 + min(UL[i - 1][j],UL[i][j - 1]));

    for (int i = 1; i <= m; i++)
      for (int j = n; j; j--)
        UR[i][j] = (a[i][j] != a[i - 1][j] || a[i][j] != a[i][j + 1]) ? 0 : (1 + min(UR[i - 1][j],UR[i][j + 1]));

    for (int i = m; i; i--)
      for (int j = 1; j <= n; j++)
        BL[i][j] = (a[i][j] != a[i + 1][j] || a[i][j] != a[i][j - 1]) ? 0 : (1 + min(BL[i + 1][j],BL[i][j - 1]));

    for (int i = m; i; i--)
      for (int j = n; j; j--)
        BR[i][j] = (a[i][j] != a[i + 1][j] || a[i][j] != a[i][j + 1]) ? 0 : (1 + min(BR[i + 1][j],BR[i][j + 1]));

    int crx = 0,cry = 0,ret = -1;
    for (int i = 1; i <= m; i++)
      for (int j = 1; j <= n; j++)
      {
            int ans = min(UL[i][j],UR[i][j]);
            ans = min(ans,BL[i][j]);
            ans = min(ans,BR[i][j]);
            if (ret < ans)
            {
                ret = ans;  crx = i;  cry = j;
            }
        }

    printf("%d %d %d\n", crx, cry, ret);
}