Submission #26354945

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Source Code Expand

#pragma GCC optimize (3, "Ofast", "inline")
#include <bits/stdc++.h>
#include <bits/extc++.h>
using namespace std;

typedef long long ll;
typedef pair <int, int> pii;

#define fi first
#define se second
#define rez resize
#define pb push_back
#define mkp make_pair
#define eb emplace_back
#define debug(...) fprintf (stderr, __VA_ARGS__)

#define Lep(i, l, r) for (int i = l; i < r; ++ i)
#define Rep(i, r, l) for (int i = r; i > l; -- i)
#define lep(i, l, r) for (int i = l; i <= r; ++ i)
#define rep(i, r, l) for (int i = r; i >= l; -- i)

const int mod = 1e9 + 7;

inline int mul (int x, int y) { return 1ll * x * y % mod; }
inline void sub (int &x, int y) { x -= y; if (x < 0) x += mod; }
inline void pls (int &x, int y) { x += y; if (x >= mod) x -= mod; }
inline int dec (int x, int y) { x -= y; if (x < 0) x += mod; return x; }
inline int add (int x, int y) { x += y; if (x >= mod) x -= mod; return x; }
inline int modpow (int x, ll y, int res = 1) {
	for (y = (y + mod - 1) % (mod - 1); y; y >>= 1, x = mul (x, x)) if (y & 1) res = mul (x, res);
	return res;
}

char _c; bool _f; template <class T> inline void IN (T & x) {
	x = 0, _f = 0; while (_c = getchar (), ! isdigit (_c)) if (_c == '-') _f = 1;
	while (isdigit (_c)) x = x * 10 + _c - '0', _c = getchar (); if (_f) x = -x;
}

template <class T> inline void chkmin (T & x, T y) { if (x > y) x = y; }
template <class T> inline void chkmax (T & x, T y) { if (x < y) x = y; }

const int N = 6e2 + 5;

int n, a[N], tag[N], f[N][N], g[N][N];

int main () {
	IN (n), n <<= 1;
	lep (i, 1, n) IN (a[i]);

	lep (i, 1, n) if (~ a[i]) tag[a[i]] = 1;
	for (int i = 1; i < n; i += 2)
		if (~ a[i] && ~ a[i + 1]) tag[a[i]] = tag[a[i + 1]] = 2;

	int tn = 0, ts = 0;
	f[0][0] = 1;

	rep (i, n, 1) if (tag[i] < 2) {
		lep (j, 0, tn) lep (k, 0, ts) {
			pls (g[j + (tag[i] == 0)][k + (tag[i] == 1)], f[j][k]);

			if (j) pls (g[j - 1][k], f[j][k]);
			if (tag[i] == 0 && k) pls (g[j][k - 1], mul (f[j][k], k));
		}

		tn += (tag[i] == 0), ts += (tag[i] == 1);
		lep (j, 0, tn) lep (k, 0, ts) f[j][k] = g[j][k], g[j][k] = 0;
	}

	int ans = f[0][0];
	rep (i, (tn - ts) >> 1, 1) ans = mul (ans, i);
	printf ("%d\n", ans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘void IN(T&)’:
./Main.cpp:36:2: warning: this ‘while’ clause does not guard... [-Wmisleading-indentation]
   36 |  while (isdigit (_c)) x = x * 10 + _c - '0', _c = getchar (); if (_f) x = -x;
      |  ^~~~~
./Main.cpp:36:63: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘while’
   36 |  while (isdigit (_c)) x = x * 10 + _c - '0', _c = getchar (); if (_f) x = -x;
      |                                                               ^~

Judge Result