public class Sys {
//其他进制转换为10进制
public int toTen(String other,int k){
StringBuilder sb=new StringBuilder(other);
String str=sb.reverse().toString();
int length=str.length();
int sum=0;
for(int i=0;i<length;i++){
int tar=str.charAt(i)-'0';
sum+=Math.pow(k,i)*tar;
}
return sum;
}
//其他进制转换为2进制
public String toTwo(String other,int k){
int sum=toTen(other,k);
StringBuilder stringBuilder=new StringBuilder();
while((sum/2)!=0){
stringBuilder.append(sum%2);
sum=sum/2;
}
if(sum==1) stringBuilder.append(1);
String result=stringBuilder.reverse().toString();
return result;
}
public static void main(String[]args){
Sys s=new Sys();
System.out.println(s.toTwo("1211012122101",3));
}
}