RT，https://ti.luogu.com.cn/problemset/1105 GESP5级中 T5答案有误，应选B，答案为A

#include <bits/stdc++.h>
#define ll long long
using namespace std;
void R(char *s,int len)
{
	if(len<=1) cout<<s[0];
	else cout<<s[0],R(s+1,len-1);
}
int main()
{
	char s[100]="Hello";
	R(s,strlen(s));
	return 0;
}