递归实现ab

#include<iostream>
using namespace std;
const int N = 5;
double fun(double a,double b){

　　return a==1?b:b+fun(a-1,b);

}

void main(){
double a[N] = {10,9,8,7,6};
double b[N] = {5,6,7,8,9};
int i = 0;
　　while(i < 5){
　　　　cout << a[i] << b[i] << "result:" << fun(a[i],b[i]) << endl;
　　　　i++;
　　　　}
}

测试结果：