Submission #1001126

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Source Code Expand

#include <stdio.h>
#include <algorithm>
using namespace std;

const long long mod = 1000000007;

long long fpow(long long a, long long p)
{
	long long r = 1;
	while (p){
		if (p & 1) r = r * a % mod;
		a = a * a % mod;
		p /= 2;
	}
	return r;
}

int N, b[303][303];
long long first[303], mul[303];
long long cnt[303][303][303];

long long go(int n, int m, int r)
{
	if (r < 0) return 0;
	if (n == 0 || m == 0) return r == 0;
	if (cnt[n][m][r] != -1) return cnt[n][m][r];
	long long &res = cnt[n][m][r]; res = 0;
	res = go(n, m - 1, r-1);
	res = (res + go(n - 1, m - 1, r) * (fpow(2, n) - 1) % mod * fpow(2, m - 1)) % mod;
	return res;
}

int main()
{
	scanf("%d", &N);
	for (int i = 0; i < N; i++) for (int j = 0; j < N; j++) scanf("%d", &b[i][j]);

	for (int i = 0; i <= N; i++) for (int j = 0; j <= N; j++) for (int k = 0; k <= N; k++) cnt[i][j][k] = -1;

	int rank = 0;
	for (int i = 0, s = 0; i < N; i++, s++){
		bool g = 0;
		for (int j = i; j < N; j++) if (b[j][s]){
			if (i != j) for (int k = 0; k < N; k++) swap(b[i][k], b[j][k]);
			g = 1;
		}
		if (!g){
			rank++;
			continue;
		}
		for (int j = i + 1; j < N; j++) if (b[j][s]){
			for (int k = 0; k < N; k++) b[j][k] ^= b[i][k];
		}
	}

	first[1] = 1;
	mul[0] = 3;
	for (int i = 2; i <= N; i++){
		first[i] = first[i - 1] * fpow(2, i - 1) % mod * (fpow(2, i) - 1) % mod;
		long long sum = 0, now = first[i];
		for (int j = 0; j < i; j++){
			sum = (sum + now * go(i, i, j)) % mod;
			if (j < i-1) now = now * mul[j] % mod;
		}
		mul[i-1] = (fpow(2,i*i*2) - sum + mod)* fpow(now, mod - 2) % mod;
	}
	long long ans = first[N];
	for (int i = 0; i < rank; i++) ans = ans * mul[i] % mod;
	printf("%lld\n", ans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:35:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
                 ^
./Main.cpp:36:79: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for (int i = 0; i < N; i++) for (int j = 0; j < N; j++) scanf("%d", &b[i][j]);
                                                                               ^

Judge Result