Submission #1110350


Source Code Expand

#include <cstdio>
#include <iostream>
#include <vector>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <string>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <functional>
#include <queue>
#include <stack>
#include <cmath>
#include <iomanip>
#include <list>
#include <tuple>
#include <bitset>
#include <ciso646>
#include <cassert>

using namespace std;

#define int long long
#define double long double

typedef pair<int, int> P;
typedef tuple<int, int, int> T;

template<class T> string tostr(T x) { stringstream o; o << x; return o.str(); }
template<class T> T sqr(T x) { return x*x; }
template<class T> T mypow(T x, int n) { T r = 1; while (n > 0) { if (n & 1)r = r*x; x = x*x; n >>= 1; }return r; }

int toint(string s) { int v; stringstream i(s); i >> v; return v; }
bool check(int x, int y, int w, int h) { return x >= 0 && y >= 0 && w > x && h > y; }
int gcd(int a, int b) { return b ? gcd(b, a%b) : a; }
int lcm(int a, int b) { return a / gcd(a, b) * b; }

#define REP(i,a,b)	for(int (i) = (a);i < (b);(i)++)
#define rep(i,n)	REP(i,0,n)
#define PER(i,a,b)	for(int (i) = (a-1);i >= (b);(i)--)
#define per(i,n)	PER(i,n,0)
#define each(i,n)	for(auto &i : n)
#define clr(a)		memset((a), 0 ,sizeof(a))
#define mclr(a)		memset((a), -1 ,sizeof(a))
#define all(a)		(a).begin(),(a).end()
#define dump(val) 	cerr << #val " = " << val << endl;
#define dum(val)	cerr << #val " = " << val;
#define FILL(a,v)	fill(a,a+sizeof(a)/sizeof(*a),v)

const int dx[8] = { +1,+0,-1,+0,+1,+1,-1,-1 };
const int dy[8] = { +0,-1,+0,+1,-1,+1,-1,+1 };
const int mod = 1e9 + 7;
const int INF = 1e17 + 9;

int mod_pow(int x, int n, int mod) {
	int res = 1;
	while (n > 0) {
		if (n & 1)res = res * x % mod;
		x = x * x % mod;
		n >>= 1;
	}
	return res;
}

signed main() {
	cin.tie(0);
	ios_base::sync_with_stdio(false);

	int n;
	cin >> n;

	map<int, int> mp;
	for (int i = 0; i < n; i++) {
		int a;
		cin >> a;
		mp[a]++;
	}

	auto zero = [&]() {
		cout << 0 << endl; exit(0);
	};

	if (n % 2) {
		if (mp[0] != 1) zero();
		for (int i = 2; i <= n - 1; i += 2) {
			if (mp[i] != 2)zero();
		}
	}
	else {
		for (int i = 1; i <= n - 1; i += 2) {
			if (mp[i] != 2)zero();
		}
	}

	cout << mod_pow(2, n / 2, mod) << endl;

	return 0; 
}

Submission Info

Submission Time
Task C - Lining Up
User omu
Language C++14 (GCC 5.4.1)
Score 300
Code Size 2372 Byte
Status AC
Exec Time 39 ms
Memory 4224 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 300 / 300
Status
AC × 3
AC × 11
Set Name Test Cases
Sample sample_01.txt, sample_02.txt, sample_03.txt
All subtask_1_invalid_01.txt, subtask_1_invalid_02.txt, subtask_1_max_01.txt, subtask_1_max_02.txt, subtask_1_max_valid_01.txt, subtask_1_max_valid_02.txt, subtask_1_min_valid_01.txt, subtask_1_rand_01.txt, subtask_1_rand_02.txt, subtask_1_valid_01.txt, subtask_1_valid_02.txt
Case Name Status Exec Time Memory
sample_01.txt AC 3 ms 256 KB
sample_02.txt AC 3 ms 256 KB
sample_03.txt AC 3 ms 256 KB
subtask_1_invalid_01.txt AC 29 ms 2944 KB
subtask_1_invalid_02.txt AC 7 ms 768 KB
subtask_1_max_01.txt AC 37 ms 4224 KB
subtask_1_max_02.txt AC 37 ms 4224 KB
subtask_1_max_valid_01.txt AC 39 ms 3328 KB
subtask_1_max_valid_02.txt AC 39 ms 3328 KB
subtask_1_min_valid_01.txt AC 3 ms 256 KB
subtask_1_rand_01.txt AC 22 ms 2688 KB
subtask_1_rand_02.txt AC 34 ms 3840 KB
subtask_1_valid_01.txt AC 21 ms 1920 KB
subtask_1_valid_02.txt AC 9 ms 896 KB