Submission #994627

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define fi first
#define se second
#define mp make_pair
#define pb push_back

#define P 1000000007

#define N 210
int n, m;
string a[N];

int ff(string a, string b, string c, string d) {
	multiset<string> u;
	u.insert(a);
	u.insert(b);
	u.insert(c);
	u.insert(d);
	a = *u.begin();
	u.erase(u.begin());
	b = *u.begin();
	u.erase(u.begin());
	c = *u.begin();
	u.erase(u.begin());
	d = *u.begin();
	u.erase(u.begin());
	if (a == b && b == c && c == d) return 1;
	if (a == b && b == c || b == c && c == d) return 4;
	if (a == b && c == d) return 6;
	if (a == b || b == c || c == d) return 12;
	return 12;
}

bool gg(string a, string b, string c, string d) {
	multiset<string> u;
	u.insert(a);
	u.insert(b);
	u.insert(c);
	u.insert(d);
	a = *u.begin();
	u.erase(u.begin());
	b = *u.begin();
	u.erase(u.begin());
	c = *u.begin();
	u.erase(u.begin());
	d = *u.begin();
	u.erase(u.begin());
	if (a != b && b != c && c != d) return true;
	return false;
}

bool b[N], c[N];

int main() {
	cin >> n >> m;
	for (int i = 0; i < n; i ++) {
		cin >> a[i];
	}
	ll S = 1;
	for (int i = 0; i*2 < n-1; i ++)
		for (int j = 0; j*2 < m-1; j ++) {
			S = (ll)S*ff(string(1, a[i][j]), string(1, a[n-1-i][j]), string(1, a[n-1-i][m-1-j]), string(1, a[i][m-1-j]))%P;
			if (gg(string(1, a[i][j]), string(1, a[n-1-i][j]), string(1, a[n-1-i][m-1-j]), string(1, a[i][m-1-j]))) b[i] = c[j] = true;
		}
	/*
	for (int i = 0; i*2 < n-1; i ++) {
		int j = 0;
		S = (ll)S*gg(string(1, a[i][j]), string(1, a[n-1-i][j]), string(1, a[n-1-i][m-1-j]), string(1, a[i][m-1-j]))%P;
	}
	for (int j = 1; j*2 < m-1; j ++) {
		int i = 0;
		S = (ll)S*gg(string(1, a[i][j]), string(1, a[n-1-i][j]), string(1, a[n-1-i][m-1-j]), string(1, a[i][m-1-j]))%P;
	}
	*/
	int T = 0;
	for (int i = 0; i*2 < n-1; i ++) if (b[i]) T ++;
	for (int j = 0; j*2 < m-1; j ++) if (c[j]) T ++;
	for (int i = 0; i < T-1; i++) S = (ll)S*2%P;
	if (n&1) {
		bool F = true;
		for (int i = 0; i < m; i++)
			if (a[n/2][i] != a[n/2][m-1-i]) F = false;
		if (!F) S = (ll)S*2%P;
	}
	if (m&1) {
		bool F = true;
		for (int i = 0; i < n; i++)
			if (a[i][m/2] != a[n-1-i][m/2]) F = false;
		if (!F) S = (ll)S*2%P;
	}
	cout << S << endl;
	return 0;
}

Submission Info

Judge Result