| Task: | Ruudukko | 
| Sender: | Olli | 
| Submission time: | 2018-10-02 15:52:11 +0300 | 
| Language: | C++ | 
| Status: | READY | 
| Result: | 14 | 
| group | verdict | score | 
|---|---|---|
| #1 | WRONG ANSWER | 0 | 
| #2 | ACCEPTED | 14 | 
| #3 | RUNTIME ERROR | 0 | 
| test | verdict | time | group | |
|---|---|---|---|---|
| #1 | ACCEPTED | 0.01 s | 1 | details | 
| #2 | ACCEPTED | 0.03 s | 1 | details | 
| #3 | ACCEPTED | 0.01 s | 1 | details | 
| #4 | ACCEPTED | 0.03 s | 1 | details | 
| #5 | ACCEPTED | 0.02 s | 1 | details | 
| #6 | ACCEPTED | 0.02 s | 1 | details | 
| #7 | ACCEPTED | 0.02 s | 1 | details | 
| #8 | WRONG ANSWER | 0.03 s | 1 | details | 
| #9 | ACCEPTED | 0.02 s | 1 | details | 
| #10 | WRONG ANSWER | 0.02 s | 1 | details | 
| #11 | ACCEPTED | 0.02 s | 2 | details | 
| #12 | ACCEPTED | 0.01 s | 2 | details | 
| #13 | ACCEPTED | 0.02 s | 2 | details | 
| #14 | ACCEPTED | 0.05 s | 2 | details | 
| #15 | ACCEPTED | 0.06 s | 2 | details | 
| #16 | ACCEPTED | 0.10 s | 2 | details | 
| #17 | ACCEPTED | 0.12 s | 2 | details | 
| #18 | ACCEPTED | 0.12 s | 2 | details | 
| #19 | ACCEPTED | 0.11 s | 2 | details | 
| #20 | ACCEPTED | 0.12 s | 2 | details | 
| #21 | RUNTIME ERROR | 0.12 s | 3 | details | 
| #22 | RUNTIME ERROR | 0.12 s | 3 | details | 
| #23 | RUNTIME ERROR | 0.12 s | 3 | details | 
| #24 | RUNTIME ERROR | 0.12 s | 3 | details | 
| #25 | WRONG ANSWER | 0.12 s | 3 | details | 
| #26 | RUNTIME ERROR | 0.12 s | 3 | details | 
| #27 | RUNTIME ERROR | 0.12 s | 3 | details | 
| #28 | RUNTIME ERROR | 0.11 s | 3 | details | 
| #29 | WRONG ANSWER | 0.12 s | 3 | details | 
| #30 | ACCEPTED | 0.11 s | 3 | details | 
Compiler report
input/code.cpp: In function 'int main()':
input/code.cpp:298:8: warning: unused variable 'hits' [-Wunused-variable]
   bool hits = false;
        ^~~~
input/code.cpp:320:8: warning: unused variable 'hits' [-Wunused-variable]
   bool hits = false;
        ^~~~Code
#include <iostream>
#include <queue>
#include <vector>
using namespace std;
bool printStuff = false;
typedef long long ll;
const int N = 555;
const int M = 1e9 + 7;
char t[N][N];
ll n;
int aA;
int amB;
void swaR(int a, int b) {
	for(int x = 1; x <= n; ++x) {
		char c = t[a][x];
		char d = t[b][x];
		t[a][x] = d;
		t[b][x] = c;
	}
}
void swaC(int a, int b) {
	for(int y = 1; y <= n; ++y) {
		char c = t[y][a];
		char d = t[y][b];
		t[y][a] = d;
		t[y][b] = c;
	}
}
void print() {
	for(int y = 1; y <= n; ++y) {
		for(int x = 1; x <= n; ++x) {
			cout << t[y][x];
		}
		cout << "\n";
	}
	cout << "\n";
}
void sor() {
	vector<int> broken;
	for(int y = n; y >= n - amB + 1; --y) {
		bool conB = false;
		for(int x = 1; x <= n; ++x) {
			if(t[y][x] == 'B') {
				conB = true;
				break;
			}
		}
		if(!conB) broken.push_back(y);
	}
	for(int y = n - amB; y >= 1; --y) {
		bool conB = false;
		for(int x = 1; x <= n; ++x) {
			if(t[y][x] == 'B') {
				conB = true;
				break;
			}
		}
		if(!conB) {
			continue;
		}
		int k = broken[broken.size() - 1];
		swaR(k, y);
		broken.pop_back();
	}
	for(int y = n; y >= n - amB + 1; --y) {
		int col = -1;
		for(int x = 1; x <= n; ++x) {
			if(t[y][x] == 'B') {
				col = x;
			}
		}
		swaC(n - y + 1, col);
	}
	aA = 0;
	for(int x = amB + 1; x <= n; ++x) {
		for(int y = n - amB; y >= 1; --y) {
			if(t[y][x] == 'A') {
				++aA;
			}
		}
	}
	for(int y = n - amB; y >= n - amB - aA + 1; --y) {
		bool conA = false;
		for(int x = amB + 1; x <= n; ++x) {
			if(t[y][x] == 'A') {
				conA = true;
				break;
			}
		}
		if(!conA) {
			broken.push_back(y);
		}
	}
	for(int y = n - amB - aA; y >= 1; --y) {
		bool conA = false;
		for(int x = amB + 1; x <= n; ++x) {
			if(t[y][x] == 'A') {
				conA = true;
				break;
			}
		}
		if(conA) {
			int k = broken[broken.size() - 1];
			swaR(k, y);
			broken.pop_back();
		}
	}
	for(int y = n - amB; y >= n - amB - aA + 1; --y) {
		int col = -1;
		for(int x = amB + 1; x <= n; ++x) {
			if(t[y][x] == 'A') {
				col = x;
				break;
			}
		}
		swaC(n - y + 1, col);
	}
	if(printStuff) {
		cout << n << "\n";
		print();
	}
}
ll dp[N][N];
void fillDP() {
	dp[0][0] = 1;
	for(int x = 1; x <= n; ++x) {
		dp[x][0] = dp[x-1][0]*x;
		dp[x][0] %= M;
	}
	for(ll y = 1; y <= n; ++y) {
		for(ll x = y; x <= n; ++x) {
			dp[x][y] = dp[x-1][y-1]*(x-y);
			dp[x][y] %= M;
			if(y == 1) continue;
			dp[x][y] += dp[x-1][y-2]*(y-1);
			dp[x][y] %= M;
		}
	}
}
ll exp(ll a, ll e) {
	if(e == 0) return 1;
	if(e%2 == 0)  {
		ll c = exp(a, e/2);
		return (c*c)%M;
	}
	ll c = exp(a, e-1);
	return (c*a)%M;
}
ll fact[N];
ll binom[N][N];
bool marked[N];
int main() {
	cin >> n;
	for(int y = 1; y <= n; ++y) {
		for(int x = 1; x <= n; ++x) {
			char c;
			cin >> c;
			t[y][x] = c;
			if(c == 'B') ++amB;
		}
	}
	sor();
	fillDP();
	fact[0] = 1;
	for(ll i = 1; i <= n; ++i) {
		fact[i] = fact[i-1]*i;
		fact[i] %= M;
	}
	for(int m = 0; m <= n; ++m) {
		for(int k = 0; k <= m; ++k) {
			ll b = fact[m];
			b *= exp(fact[k], M-2);
			b %= M;
			b *= exp(fact[m-k], M-2);
			b %= M;
			binom[m][k] = b;
		}
	}
	ll ans = 0;
	int a1 = 0;
	int a2 = 0;
	int a3 = 0;
	//calculate a2
	for(int y = 1; y <= n - amB - aA; ++y) {
		for(int x = 1; x <= amB; ++x) {
			if(t[y][x] == 'A') {
				++a2;
			}
		}
	}
	//calculate a3;
	for(int y = n - amB; y <= n; ++y) {
		for(int x = amB + aA + 1; x <= n; ++x) {
			if(t[y][x] == 'A') {
				++a3;
			}
		}
	}
	//calculate a1;
	for(int x = 1; x <= amB; ++x) {
		for(int y = n - amB + 1; y <= n; ++y) {
			if(t[y][x] == 'A') {
				++a1;
			}
		}
	}
/*
	for(int i = 0; i <= n; ++i) {
		for(int a = 0; a <= i; ++a) {
			cout << dp[i][a] << " ";
		}
		cout << "\n";
	}
	cout << "\n";
*/
	int initialB = 0;
	//How many B:s have been hit initially
	for(int x = 1; x <= amB; ++x) {
		for(int y = 1; y <= n; ++y) {
			if(t[y][x] == 'A') {
				if(!marked[x]) {
					++initialB;
					marked[x] = true;
				}
			}
		}
	}
	for(int y = n - amB + 1; y <= n; ++y) {
		for(int x = amB + 1; x <= n; ++x) {
			if(t[y][x] == 'A') {
				if(!marked[n - y + 1]) {
					++initialB;
					marked[n-y+1] = true;
				}
			}
		}
	}
	int hitAbove = 0;
	int noHitAbove = 0;
	int hitRight = 0;
	int noHitRight = 0;
	for(int x = 1; x <= amB; ++x) {
		bool contains = false;
		for(int y = 1; y <= n; ++y) {
			if(t[y][x] == 'A') {
				contains = true;
				break;
			}
		}
		if(contains) continue;
		bool hits = false;
		for(int y = 1; y <= n; ++y) {
			if(t[y][x] == 'B') {
				if(marked[x]) {
					++noHitAbove;
				} else {
					++hitAbove;
				}
				break;
			}
		}
	}
	for(int y = n - amB + 1; y <= n; ++y) {
		bool contains = false;
		for(int x = 1; x <= n; ++x) {
			if(t[y][x] == 'A') {
				contains = true;
				break;
			}
		}
		if(contains) continue;
		bool hits = false;
		for(int x = 1; x <= n; ++x) {
			if(t[y][x] == 'B') {
				if(marked[x]) {
					++noHitRight;
				} else {
					++hitRight;
				}
				break;
			}
		}
	}
	for(ll f2 = max(a2, a3); f2 <= min((ll) amB - a1, n - amB - aA); ++f2) {
		for(int amountOfB = initialB; amountOfB <= amB; ++amountOfB) {
			//We will have amountOfB of B:s that have been hit
			//We have to hit amountOfB - initialB more
			ll A23 = 0;
			int t = amountOfB - initialB;
			if(t > f2 - a2 + f2 - a3) continue;
			int s = n - amB - aA;
			
			if(printStuff) {
				cout << "\n\n";
				cout << "The configuration we have: \n";
				cout << "We have to hit " << t << " more B:s\n";
				cout << "We should add " << f2 - a2 << " and " << f2 - a3 << " new ones \n";
				cout << "There are " << noHitAbove << " and " << noHitRight << " choices that do not hit\n";
				cout << "and " << hitAbove << " and " << hitRight << " choices that hit a new one \n";
			}
			for(int o2 = 0; o2 <= t; ++o2) {
				int d2 = f2 - a2;
				ll A2 = binom[noHitAbove][d2 - o2]*binom[hitAbove][o2];
				A2 %= M;
				A2 *= binom[s - a2][d2];
				A2 %= M;
				
				int o3 = t - o2;
				int d3 = f2 - a3;
				if(o3 > d3) continue;
				ll A3 = binom[hitRight - o2][o3] * binom[noHitRight + o2][d3];
				A3 %= M;
				A3 *= binom[s - a3][d3];
				A3 %= M;
				A23 += A2*A3;
				A23 %= M;
			}
			if(printStuff) {
				cout << "The result is, we have " << A23 << " choices for the A:s\n";
			}
			if(A23 == 0) continue;
			ll f1 = amB - f2;
			ll d1 = f1 - a1;
			ll A1 = dp[d1][amB- amountOfB];
			if(printStuff) {
				cout << "In this case we have " << A1 << " choices for A1\n";
				cout << "That's because we added " << d1 << " new A:s to the grid\n";
				cout << "and there are " << amB - amountOfB << " B:s in the small area\n";
			}
			ll f4 = n - 2*f2 - f1 - aA;
			ll A4 = 1;
			for(ll i = 1; i <= f4; ++i) {
				A4 *= i;
				A4 %= M;
			}
			ll B = dp[n - amB][aA + f4];
			ll cur = A23;
			cur %= M;
			cur *= A1;
			cur %= M;
			cur *= A4;
			cur %= M;
			cur *= B;
			cur %= M;
			if(printStuff) {
				cout << "Statistics for " << f2 << " " << amountOfB << "\n";
				cout << "Number of ways for A:s " << A1*A23*A4 << "\n";
				cout << "Number of ways for A1 is " << A1 << " and for A23 it's " << A23 << " and for A4 " << A4 << "\n";
				cout << "Number of ways for B:s " << B << "\n";
				cout << "Total number of ways: " << A1*A23*A4*B << "\n";
				cout << "\n\n";
			}
			ans += cur;
			ans %= M;
		}
	}
	cout << ans << "\n";
}
Test details
Test 1
Group: 1
Verdict: ACCEPTED
| input | 
|---|
| 2 .. .. | 
| correct output | 
|---|
| 2 | 
| user output | 
|---|
| 2 | 
Test 2
Group: 1
Verdict: ACCEPTED
| input | 
|---|
| 2 .. A. | 
| correct output | 
|---|
| 1 | 
| user output | 
|---|
| 1 | 
Test 3
Group: 1
Verdict: ACCEPTED
| input | 
|---|
| 2 B. .A | 
| correct output | 
|---|
| 0 | 
| user output | 
|---|
| 0 | 
Test 4
Group: 1
Verdict: ACCEPTED
| input | 
|---|
| 3 ... ... ... | 
| correct output | 
|---|
| 12 | 
| user output | 
|---|
| 12 | 
Test 5
Group: 1
Verdict: ACCEPTED
| input | 
|---|
| 4 .... .... .... .... | 
| correct output | 
|---|
| 216 | 
| user output | 
|---|
| 216 | 
Test 6
Group: 1
Verdict: ACCEPTED
| input | 
|---|
| 5 ..... ..... ..... ..... ... | 
| correct output | 
|---|
| 5280 | 
| user output | 
|---|
| 5280 | 
Test 7
Group: 1
Verdict: ACCEPTED
| input | 
|---|
| 5 ....A ..... ..... ..... ... | 
| correct output | 
|---|
| 264 | 
| user output | 
|---|
| 264 | 
Test 8
Group: 1
Verdict: WRONG ANSWER
| input | 
|---|
| 5 B.... ..... ..... .A.B. ... | 
| correct output | 
|---|
| 22 | 
| user output | 
|---|
| 2 | 
Test 9
Group: 1
Verdict: ACCEPTED
| input | 
|---|
| 5 B.A.. ....A ..... A.B.. ... | 
| correct output | 
|---|
| 2 | 
| user output | 
|---|
| 2 | 
Test 10
Group: 1
Verdict: WRONG ANSWER
| input | 
|---|
| 5 A.B.. BA... .B.A. ...BA ... | 
| correct output | 
|---|
| 1 | 
| user output | 
|---|
| 0 | 
Test 11
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 10 .......... .......... .......... .......... ... | 
| correct output | 
|---|
| 306442892 | 
| user output | 
|---|
| 306442892 | 
Test 12
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 50 ................................. | 
| correct output | 
|---|
| 694861480 | 
| user output | 
|---|
| 694861480 | 
Test 13
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 111 ................................. | 
| correct output | 
|---|
| 555319110 | 
| user output | 
|---|
| 555319110 | 
Test 14
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 222 ................................. | 
| correct output | 
|---|
| 108372237 | 
| user output | 
|---|
| 108372237 | 
Test 15
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 333 ................................. | 
| correct output | 
|---|
| 259107857 | 
| user output | 
|---|
| 259107857 | 
Test 16
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 444 ................................. | 
| correct output | 
|---|
| 19906314 | 
| user output | 
|---|
| 19906314 | 
Test 17
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 497 ................................. | 
| correct output | 
|---|
| 224313667 | 
| user output | 
|---|
| 224313667 | 
Test 18
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 498 ................................. | 
| correct output | 
|---|
| 929574601 | 
| user output | 
|---|
| 929574601 | 
Test 19
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 499 ................................. | 
| correct output | 
|---|
| 600226043 | 
| user output | 
|---|
| 600226043 | 
Test 20
Group: 2
Verdict: ACCEPTED
| input | 
|---|
| 500 ................................. | 
| correct output | 
|---|
| 198353194 | 
| user output | 
|---|
| 198353194 | 
Test 21
Group: 3
Verdict: RUNTIME ERROR
| input | 
|---|
| 499 ................................. | 
| correct output | 
|---|
| 840243733 | 
| user output | 
|---|
| (empty) | 
Test 22
Group: 3
Verdict: RUNTIME ERROR
| input | 
|---|
| 499 ........................A........ | 
| correct output | 
|---|
| 4146290 | 
| user output | 
|---|
| (empty) | 
Test 23
Group: 3
Verdict: RUNTIME ERROR
| input | 
|---|
| 499 B.........A...................... | 
| correct output | 
|---|
| 173518884 | 
| user output | 
|---|
| (empty) | 
Test 24
Group: 3
Verdict: RUNTIME ERROR
| input | 
|---|
| 499 ...A....B........................ | 
| correct output | 
|---|
| 20044800 | 
| user output | 
|---|
| (empty) | 
Test 25
Group: 3
Verdict: WRONG ANSWER
| input | 
|---|
| 499 AB............................... | 
| correct output | 
|---|
| 2 | 
| user output | 
|---|
| 1 | 
Test 26
Group: 3
Verdict: RUNTIME ERROR
| input | 
|---|
| 500 ................................. | 
| correct output | 
|---|
| 121064146 | 
| user output | 
|---|
| (empty) | 
Test 27
Group: 3
Verdict: RUNTIME ERROR
| input | 
|---|
| 500 ................................. | 
| correct output | 
|---|
| 848435259 | 
| user output | 
|---|
| (empty) | 
Test 28
Group: 3
Verdict: RUNTIME ERROR
| input | 
|---|
| 500 .....B........A.................. | 
| correct output | 
|---|
| 296240911 | 
| user output | 
|---|
| (empty) | 
Test 29
Group: 3
Verdict: WRONG ANSWER
| input | 
|---|
| 500 .A......B........................ | 
| correct output | 
|---|
| 2196 | 
| user output | 
|---|
| 930 | 
Test 30
Group: 3
Verdict: ACCEPTED
| input | 
|---|
| 500 ...AB............................ | 
| correct output | 
|---|
| 1 | 
| user output | 
|---|
| 1 | 
