题解 | 牛牛学数列2

#include <stdio.h>
double Sum(int n) {
    if (n == 1) {
        return 1;
    }
    return 1 * 1.0 / n + Sum(n - 1);
}
int main() {
    int n = 0;
    double result;
    scanf("%d", &n);
    result = Sum(n);
    printf("%lf", result);
    return 0;
}