十进制N转化为R进制
import java.util.Scanner;
public class Main{
public static void main(String[] args){
Scanner s=new Scanner(System.in);
int N=s.nextInt();
int R=s.nextInt();
int m,now;
if(N<0){
System.out.print("-");
N=-N;
}
char []a=new char[105];
while(N){//当N!=0
now=N%R;
if(now<=9){
a[m++]=(char)(‘0’+now);
}else{
a[m++]=(char)(‘A’+(now-10));//注意此时结果是大写
}
N/=R;
}
if(m==0)
System.out.print(“0”);
for(int i=m-1;i>=0;i–){
System.out.print(a[i]);
}
}
}