求100以内素数的倒数和

以下是求100以内素数的倒数和的代码示例：

#include<iostream>
using namespace std;

bool isPrime(int num) {
    if (num <= 1) {
        return false;
    }
    for (int i = 2; i <= num / 2; i++) {
        if (num % i == 0) {
            return false;
        }
    }
    return true;
}

double reciprocalSum(int n) {
    double sum = 0;
    for (int i = 2; i <= n; i++) {
        if (isPrime(i)) {
            sum += 1.0 / i;
        }
    }
    return sum;
}

int main() {
    int n;
    cin >> n;
    double sum = reciprocalSum(n);
    cout << sum << endl;
}