题解 | #牛牛学数列2#

#include <stdio.h>

int main() {
	int n = 0, i = 0;
	double sum = 0.0;  
	scanf("%d", &n);
	//float类型变量仅精确到小数后六位，第六位可能不准确
	//double类型精确到小数后15位，第六位是准确的
		
	for (i = 1; i <= n; i++) {
		sum += 1.0 / (double)i;
	}
	printf("%.6lf", sum);

	return 0;
}