AcWing 5398. 数组分割
原题链接
简单
作者:
拼凑回忆
,
2024-04-04 20:47:18
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所有人可见
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阅读 23
#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 1010, mod = 1000000007;
int t, n;
int j, o;
int qmi(int a, int b)
{
int res = 1 % mod;
while (b)
{
if (b & 1) res = res * a % mod;
a = a * a % mod;
b >>= 1;
}
return res;
}
signed main()
{
cin >> t;
while (t -- )
{
j = 0, o = 0;
cin >> n;
for (int i = 0; i < n; i ++ )
{
int k;
cin >> k;
if (k % 2) j ++ ;
else o ++ ;
}
if (j % 2)
{
cout << 0 << endl;
continue;
}
if (j == 0)
cout << qmi(2, n) << endl;
else
cout << qmi(2, n - 1) << endl;
}
}