求代數和sum = 1 - 1/2 + 1/3 + 1/4 - 1/5 + 1/6 + 1/7 + 1/8 - 1/9 + …
計算代數和 sum = 1 - 1/2 + 1/3 + 1/4 - 1/5 + 1/6 + 1/7 + 1/8 - 1/9 + …
//AlgebraicSum.cpp
//calculate the algebraic sum
//sum = 1 - 1/2 + 1/3 + 1/4 - 1/5 + 1/6 + 1/7 + 1/8 - 1/9 + …
#include <iostream>
#include <cstdlib> 
using namespace std;
int main()

{
int j = 1, t = 1; //用t記錄什么時候換符號
double sum = 0, n = 0; //sum 不是int類型哈 
cout << "Input an Integer n:" << endl;
cin >> n ; // 要求的代數和的n 
for (int i = 1; i != n+1; ++i ) 
{
if(t != 0) 
{
sum = sum + 1.0/i;
--t;
if (i==1) cout << i;
else cout << " + 1/" << i;
}
else
{
sum = sum - 1.0/i;
t=++j;
if(i==1) cout << i;
else cout << " - 1/" << i;
}
}
cout << " = " << sum << endl;
system("pause");
return 0;
}posted on 2009-04-28 15:54 幸運草 閱讀(1593) 評論(0) 編輯 收藏 引用 所屬分類: programming

