#include <iostream>
using namespace std;
void f(int a,int b){
if(b<=9){
if(a<=b){
cout<<a<<"x"<<b<<"="<<a*b<<" ";
f(a+1,b);
}
cout<<endl;
}
f(1,b+1);
}
int main(int argc, char** argv){
f(1,1);
return 0;
}
标签：std,九九乘法,递归,int,void,namespace From： https://www.cnblogs.com/As10016/p/17674573.html