@[nei_juan_zhe](/user/752792) 前缀和
by rainygame @ 2023-06-30 14:37:03
@[nei_juan_zhe](/user/752792) O2
by _buzhidao_ @ 2023-06-30 14:40:43
吸氧+前缀和之后70分了，谢谢两位大佬（尽管我并不满足但已经好一点了
by int__main @ 2023-06-30 14:51:00
这是 $O(n^3)$ 罢（恼
by PluviaLaver @ 2023-06-30 14:58:15
@[nei_juan_zhe](/user/752792) 前缀和+桶优化
```cpp
#include<bits/stdc++.h>
using namespace std;
int n,a[100005],g[200005],s[100005],ans;
int main(){
scanf("%d",&n);
for(int i=1;i<=n;i++){
scanf("%d",&a[i]);
if(a[i]==0) s[i]=s[i-1]-1;
else s[i]=s[i-1]+1;
if(s[i]!=0&&g[s[i]+n]==0) g[s[i]+n]=i;
}
for(int i=1;i<=n;i++){
ans=max(ans,i-g[s[i]+n]);
}
printf("%d",ans);
return 0;
}
```
by Code_Fish_Hp @ 2023-07-10 09:50:58