Lhy2009 @ 2020-12-28 19:48:16
#include<iostream>
#include<string>
using namespace std;
long long did(long long n,long long l){
if(n<=l){
return (int)n;
}
int k=did(n,2*l);
if(k<=l){
return k;
}else if(n==l+1){
return l;
}else{
return k-l-1;
}
}
int main(){
string x;
long long n;
cin>>x;
cin>>n;
n=did(n,x.length());
cout<<x[n-1]<<endl;
return 0;
}by LoneWolf @ 2020-12-28 20:38:29
@Lhy2009 咋了，啥意思？
by Lhy2009 @ 2020-12-29 14:30:57
50分，哪里错了
by Lhy2009 @ 2020-12-29 15:05:06
更新代码，60分（6ac+2re+2wa）
#include<iostream>
#include<string>
using namespace std;
long long did(long long n,long long l){
if(n<=l){
return n;
}
int k=did(n,l<<1);
if(k<=l){
return k;
}else if(k==l+1){
return l;
}else{
return k-l-1;
}
}
int main(){
string x;
long long n;
cin>>x;
cin>>n;
int k=did(n,x.length());
cout<<x[k-1]<<endl;
return 0;
}by Lhy2009 @ 2020-12-29 15:15:51
sorry,本帖终（100分）
#include<iostream>
#include<string>
using namespace std;
int main(){
string x;
long long n;
cin>>x;
cin>>n;
long long lx=x.length();
int m=0;
while(n>lx){
lx*=2;
m++;
}
for(int i=0;i<m;i++){
lx/=2;
if(n<=lx){
}else if(n==lx+1){
n=lx;
}else{
n-=(lx+1);
}
}
cout<<x[n-1]<<endl;
return 0;
}