C++(g++ 7.5.0) 解法, 执行用时: 3ms, 内存消耗: 396K, 提交时间: 2023-02-19 18:51:09

#include<bits/stdc++.h>
using namespace std;
string a;
char bfs(int l,int r){
	char c,c1,c2;
	if(l==r){
	a[l]=='1'?c='I':c='B';
	cout<<c;}
	else{
		int mid=(l+r)>>1;
		c1=bfs(l,mid);
		c2=bfs(mid+1,r);
		if(c1=='F'||c2=='F'||c1!=c2)
		c='F';
		else
		c=c1;
		cout<<c;
	}
	return c;
}
int main(){
	int n;
	cin>>n;
	cin>>a;
	bfs(0,(1<<n)-1);
	return 0;
}

Pascal(fpc 3.0.2) 解法, 执行用时: 2ms, 内存消耗: 376K, 提交时间: 2019-09-08 07:27:49

var
a,s:string;
i,n:longint;

function aa(i:longint):char;
var
l,r:char;
begin
if (1<<n)<=i then begin write(s[i-1<<n+1]); exit(s[i-1<<n+1]); end;
l:=aa(2*i);
r:=aa(2*i+1);
if l=r then begin write(l); exit(l); end;
write('F'); exit('F');
end;

begin
readln(n);
readln(a);
for i:=1 to 1<<n do
 if a[i]='1' then s:=s+'I' else s:=s+'B';
s:=s+aa(1);
end.

C++14(g++5.4) 解法, 执行用时: 3ms, 内存消耗: 596K, 提交时间: 2019-09-10 21:11:17

#include<bits/stdc++.h>
using namespace std;
int n;string s;
void dfs(int l,int r)
{
	int mid=(l+r)/2;
	if(l!=r)
	{
		dfs(l,mid);dfs(mid+1,r);
	}
	int x,y;x=y=0;
	for(int i=l;i<=r;i++)
	{
		if(s[i]=='0')	x++;else y++;
	}
    if(x&&y)	cout<<"F";if(x&&(!y))	cout<<"B";if((!x)&&y)	cout<<"I";
}
int main()
{
	cin>>n>>s;
	dfs(0,s.size()-1);
}

Python(2.7.3) 解法, 执行用时: 14ms, 内存消耗: 2828K, 提交时间: 2021-03-11 17:01:21

def fbi(s):
    l = len(s)
    if l == 1:
        return 'B' if s[0] == '0' else 'I'
    left_tree = fbi(s[0: l / 2])
    right_tree = fbi(s[l / 2:])
    root = 'F'
    if left_tree == right_tree:
        root = left_tree[-1]
    return left_tree + right_tree + root
  
n = raw_input()
n = int(n)
s = raw_input()
print fbi(s)

C++(clang++ 11.0.1) 解法, 执行用时: 2ms, 内存消耗: 404K, 提交时间: 2022-08-18 08:22:54

#include<bits/stdc++.h>
using namespace std;
void fun(string s)
{
	if(s.size()>1)
	{
		fun(s.substr(0,s.size()/2));
		fun(s.substr(s.size()/2,s.size()/2));
	}
	if(s==string(s.size(),'1'))cout<<"I";
	else if(s==string(s.size(),'0'))cout<<"B";
	else cout<<"F";
}
int main(){
	int n;
	string s;
	cin>>n>>s;
	fun(s);
	return 0;
}