为什么是0分

#include<bits/stdc++.h>
using namespace std;
int binary(int m,string s){
    int ans=0;
    for(int i=0;i<s.size();i++){
        char t=s[i];
        if(t>='0'&&t<='9'){
            ans=ans*m+t-'0';
        }
        else
        ans=ans*m+t-'a'+10;
    }
    return ans;
}
string intabjinzhi(int n,int m){
    string ans1="";
    do{
       int t1=n%m;
       if(t1>=0&&t1<=9){
           ans1+=(t1+'0');
       }
       else
       ans1+=(t1+'a'-10);
       
       n/=m;
    }while(n);
    
    return ans1;
}
int main(){
    long long n,k;
    cin>>k>>n;
    string t=intabjinzhi(10,2);
    cout<<binary(k,t)<<endl;
    return 0;
}