C语言网题目 1015: [编程入门]求和训练

#include<iostream>
using namespace std;

 int Sum1(int n)
{
	int sum = 0;
	for(int i = 1;i <= n; i++)
    {
    	sum += i;
	}
	return sum;	
}

int Sum2(int n)
{
	int sum=0,fact=1;
	for (int i=1;i<=n;i++)
	{
		fact = i * i;;
		sum+=fact;
	}
	return sum;
}

double Sum3( int n)
{
	double sum = 0;
    for(int i=1;i<=n;i++)
    {
        sum += 1.0/i;
    }
    return sum;
}

int main()
{
    int a,b,c;
    cin >> a>> b>> c;
    double sum1 = 0,sum2 = 0,sum3 = 0,sum = 0;
    sum1 = Sum1(a);
	sum2 = Sum2(b);
	sum3 = Sum3(c); 
	sum = sum1 + sum2 + sum3;
	printf("%.2lf",sum);
    return 0;
}