Question

用C++解答 计算1-1/2+1/3-1/4+....+1/10

Answer 1

#include <iostream>
using namespace std;
int main()
{
int i,f=-1;
double sum=0,a=1,s=1;
for (i=2;i <=10;i++)
{
s=s+(f*(1/a));
sum=sum+s;
f=f*(-1);
a=a+1;
}
cout<<sum<<endl;
}我没编译，你试一下，思路就这样！

Answer 2

main()
{
int i,t=1;
float sn=0;
for(i=1;i<101;i++){
sn+=(1/i)*t;
t*=-1;
}
printf("sn=%f",sn);
}
/*这个是求到1/100的，你稍稍改改。*/

Answer 3

include"iostream.h"void main().{ int i,t=1; float sn=0; for(i=1;i<101;i++) { sn+=(1.0/i)*t; t*=-1; } cout<<sn<<endl; }

Answer 4

#include<iostream.h>
void fun(int n,int& num,int& dec){ num=1; dec=((n%2==1)?-1:1)*n;}
int main() { int n,num,dec; double sum=0,an=0; for(int i=1;i<=10;i++) { fun(i,num,dec); an=(double)num/dec; cout<<"num="<<num<<"\tdec="<<dec<<"\tan="<<an<<endl; sum+=an; } cout<<"sum="<<sum<<endl; return 1;}