#include<bits/stdc++.h>
using namespace std;
int a[1025];
void treee(int x,int y)
{
if (x<y)
{
treee(x,(y/2));
treee((y/2+1),y);
}
int B=1,I=1;
for (int i=x;i<=y;++i)
{
if (a[i]) B=0;
if (!a[i]) I=0;
}
if (!B&&I) cout<<"I";
if (B&&!I) cout<<"B";
if (!B&&!I) cout<<"F";
}
int power(int x,int y)
{
int ans=1;
for (int i=1;i<=y;++i)
ans*=x;
return ans;
}
int main()
{
int n;cin>>n;
n=power(2,n);cout<<n<<endl;
for (int i=1;i<=n;++i)
cin>>a[i];
treee(1,n);
return 0;
}
代码一直在输入是为什么,求助