样例
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 400010;
int n;
int w[N];
int main()
{
int T;
scanf("%d", &T);
while (T -- )
{
scanf("%d", &n);
for (int i = 0; i < n; i ++ )
{
scanf("%d", &w[i]);
w[n + i] = w[i];
}
int res = 0;
for (int i = 0, s = 0; i < n * 2; i ++ )
if (w[i])
{
s ++ ;
res = max(res, s);
}
else s = 0;
printf("%d\n", res);
}
retuen 0;
}