/*函数：r进制转换成10进制*/
int rToTen(string n,int r){
//将r进制转为10进制，n是该r进制的字符串表示
int len = n.length();
int ans = 0;
int i = 0;
while(i<len){
ans*=r;
ans+=n[i]-'0';
i++;
}
return ans;
}
/*函数：十进制转任意进制*/
void tenToR(int n,int r){
//十进制n转r进制 ，返回字符串s
char str[1005];
memset(str,' ',sizeof(str));
stack<int>s;
while(n){
s.push(n%r);
n = n/r;
}
int i = 0;
while(!s.empty()){
switch(s.top()){
case 10:
str[i++] = 'A';
break;
case 11:
str[i++] = 'B';
break;
case 12:
str[i++] = 'C';
break;
case 13:
str[i++] = 'D';
break;
case 14:
str[i++] = 'E';
break;
case 15:
str[i++] = 'F';
break;
default:
str[i++] = s.top()+'0';
}
s.pop();
}
cout<<str<<endl;
}