C++ 代码

#include <iostream>
#include <cmath>
using namespace std;
string s;
void FBI(int left,int right)
{
    int mid=(left+right)/2;
    if(left<right)
    {
        FBI(left,mid);
        FBI(mid+1,right);   
    }   
    int zero=0,one=0;
    for(int i=left;i<=right;i++)
    {
        if(s[i]=='0')
            zero++;
        else
            one++;
    }
    if(zero==0 and one>=1)
        cout<<"I";
    if(zero>=1 and one==0)
        cout<<"B";
    if(zero>=1 and one>=1)
        cout<<"F";
} 
int main()
{
    int n,z;
    cin>>n;
    z=pow(2,n)-1;
    cin>>s;
    FBI(0,z);
    return 0;
}