42. 有如下程序：
#include <iostream>
using namespace std;
class Integer{
public:
Integer(): n(0){}
private:
int n;
};
class PosInteger: public Integer{
public:
PosInteger(): n(0){ }
void setN(int i){n = i;}
friend bool operator<(const PosInteger &b1,const PosInteger &b2);
private:
int n;
};
bool operator<(const PosInteger &b1,const PosInteger &b2){
return b1.n <b2.n;
}
int main(){
PosInteger a1,a2;
a1.setN(5);
a2.setN(10);
cout<<(a1<a2)<<endl;
return 0;
}
运行后的输出结果是______。
