POJ2185 Milking Grid

#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <vector>
#include <list>
#include <deque>
#include <queue>
#include <cctype>
#include <map>
#include <set>
#include <bitset>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
#include <cassert>
#include <limits>
#include <fstream>

using namespace std;

#define mem(A, X) memset(A, X, sizeof A)
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define foreach(e,x) for(__typeof(x.begin()) e=x.begin();e!=x.end();++e)
#define sz(x) (int)((x).size())
#define rep(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#define Rep(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define min3(a,b,c) min(a,min(b,c))
#define max3(a,b,c) max(a,max(b,c))
#define dbg(a) cout << a << endl;
#define fi first
#define se second
typedef long long int64;
int gcd(const int64 &a, const int64 &b) {return b == 0 ? a : gcd(b, a % b);}
int64 int64pow(int64 a, int64 b){if(b == 0) return 1;int64 t = int64pow(a, b / 2);if(b % 2) return t * t * a;return t * t;}
const int inf = 1 << 30;
const double eps = 1e-8;
const double pi = acos(-1.0);
const int MAX_N = 10005;

int r, c, LCM_r, LCM_c;
char s[MAX_N][85];
int next[MAX_N];

int64 lcm(const int64 &a, const int64 &b)
{
    return a * b / gcd(a, b);
}

void GetRowNext(int pos)
{
    int i = 0, j = -1;
    next[0] = -1;
    int LenP = strlen(s[pos]);

    while (i < LenP) {
        if (j == -1 || s[pos][i] == s[pos][j]) {
            ++i;
            ++j;
            next[i] = j;
        }
        else {
            j = next[j];
        }
    }
}


void GetColNext(int pos)
{
    int i = 0, j = -1;
    next[0] = -1;

    while (i < r) {
        if (j == -1 || s[i][pos] == s[j][pos]) {
            ++i;
            ++j;
            next[i] = j;
        }
        else {
            j = next[j];
        }
    }
}
void solve()
{
    LCM_r = LCM_c = 1;
    rep(i, 0, r) {
        scanf("%s", s[i]);
    }
    rep(i, 0, r) {
        GetRowNext(i);
        LCM_r = lcm(LCM_r, c - next[c]);
        if (LCM_r > c) {
            LCM_r = c;
            break;
        }
    }
    rep (i, 0, c) {
        GetColNext(i);
        LCM_c = lcm(LCM_c, r - next[r]);
        if (LCM_c > r) {
            LCM_c = r;
            break;
        }
    }
    cout << LCM_r * LCM_c << endl;
}

int main()
{
    while (cin >> r >> c) {
        solve();
    }
    return 0;
}