Submission #3464785

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Source Code Expand

#include <bits/stdc++.h>

#define For(i, l, r) for(register int i = (l), i##end = (int)(r); i <= i##end; ++i)
#define Fordown(i, r, l) for(register int i = (r), i##end = (int)(l); i >= i##end; --i)
#define Set(a, v) memset(a, v, sizeof(a))
#define Cpy(a, b) memcpy(a, b, sizeof(a))
#define debug(x) cout << #x << ": " << (x) << endl
#define DEBUG(...) fprintf(stderr, __VA_ARGS__)

using namespace std;

template<typename T> inline bool chkmin(T &a, T b) { return b < a ? a = b, 1 : 0; }
template<typename T> inline bool chkmax(T &a, T b) { return b > a ? a = b, 1 : 0; }

inline int read() {
	int x(0), sgn(1); char ch(getchar());
	for (; !isdigit(ch); ch = getchar()) if (ch == '-') sgn = -1;
	for (; isdigit(ch); ch = getchar()) x = (x * 10) + (ch ^ 48);
	return x * sgn;
}

void File() {
	freopen ("F.in", "r", stdin);
	freopen ("F.out", "w", stdout);
}

const int N = 310, Mod = 1e9 + 7;

int n; char str[N];

int dp[N][N][N];

inline void Add(int &a, int b) {
	if ((a += b) >= Mod) a -= Mod;
}

int main () {

	n = read();
	scanf ("%s", str + 1);

	int len = strlen(str + 1);

	dp[0][0][0] = 1;
	For (i, 0, n - 1) {
		For (j, 0, i) For (k, 0, j) if (dp[i][j][k]) {
			if (k) {
				Add(dp[i + 1][j + 1][k], dp[i][j][k] * 2 % Mod);
				Add(dp[i + 1][j - 1][j == k ? 0 : k], dp[i][j][k]);
			} else {
				Add(dp[i + 1][j + 1][0], dp[i][j][0]);
				Add(dp[i + 1][j + 1][j + 1], dp[i][j][0]);
				Add(dp[i + 1][max(0, j - 1)][0], dp[i][j][0]);
			}
		}
	}
	printf ("%d\n", dp[n][len][0]);

	return 0;

}

Submission Info

Compile Error

./Main.cpp: In function ‘void File()’:
./Main.cpp:23:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
  freopen ("F.in", "r", stdin);
                              ^
./Main.cpp:24:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
  freopen ("F.out", "w", stdout);
                                ^
./Main.cpp: In function ‘int main()’:
./Main.cpp:40:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%s", str + 1);
                       ^

Judge Result