撞库函数名了。
by _cyle_King @ 2022-10-04 19:58:37
`index`改成`idx`试试
by ssytxy2024 @ 2022-10-04 19:58:50
index 是万能头关键字
-----------------------改头文件罢
------------
```cpp
#include <bits/stdc++.h>
using namespace std;
const int maxn=1e6 + 10;
int a[maxn],sum[maxn],qwq[2 * maxn];
int main() {
int n;
scanf("%d",&n);
sum[0]=0;
memset(qwq,-1,sizeof(qwq));
for (int i = 1; i <= n; ++i)
{
scanf("%d", &a[i]);
if (a[i] == 0)
a[i] = -1;
sum[i] = sum[i - 1] + a[i];
int x = sum[i] + 1e6;
if (qwq[x] == -1)
qwq[x] = i;
}
int ans=0;
for(int i=2;i<=n;++i)
{
int x=sum[i]+1e6;
ans=max(ans,i-qwq[x]);
}
cout<<ans;
return 0;
}
```
by Sir_en @ 2022-10-04 20:01:10
@[Sir_en](/user/665463) 改数组或头文件
by Sir_en @ 2022-10-04 20:04:59