第1个回答 2015-02-24
//#include "stdafx.h"//vc++6.0加上这一行.
#include <iostream>
using namespace std;
int main(void){//1-1/2+1/3-1/4……1/n
int i,n;
double sum;
cout << "Input n(>0 int):\nn=";
cin >> n;
for(sum=0,i=1;i<=n;sum += i&1 ? 1.0/i++ : -1.0/i++);
cout << "The result is " << sum << endl;
return 0;
}
第2个回答 推荐于2016-06-14
#include <iostream>
using namespace std;
int main(){
int n,flag=1;
double sum=0;
cin>>n;
for(int i=1;i<=n;++i)
sum=sum+1.0/(double)i*flag,flag=-flag;
cout<<sum<<endl;
return 0;
}本回答被提问者采纳