c++编写程序计算sum=1-1/2+1/4-1/8……

以下是C++编写程序计算sum=1-1/2+1/4-1/8……的代码：

#include <iostream>
using namespace std;

int main() {
    int n;
    float sum = 1.0, temp = 1.0;
    cout << "请输入一个整数n：";
    cin >> n;
    for (int i = 1; i <= n; i++) {
        temp /= 2;
        if (i % 2 == 0) {
            sum += temp;
        } else {
            sum -= temp;
        }
    }
    cout << "sum=" << sum << endl;
    return 0;
}