Tính S(n)= 1 + (1+2)/2! + (1+2+3)/3! + ... + (1+2+3+..+n)/n! (n>0)

Trả lời

// Tính S(n)= 1 + (1+2)/2! + (1+2+3)/3! + ... + (1+2+3+..+n)/n! (n>0)

#include <iostream>

using namespace std;

int Nhap()

{

int x;

do

{

         cin >> x;

           if (x < 0)

                     cout << "Nhap sai, yeu cau nhap lai!";

} while (x < 0);

return x;

}

double Tinh(int n)

{

float s = 0, t = 0;

long p = 1;

for (int i = 1; i <= n; i++)

{

           t = t + i;

           p = p * i;

           s = s + (double)t / p;

}

return s;

}

int main()

{

int n;

 cout << "Nhap so nguyen n: ";

n = Nhap();

cout << "Ket qua la: "<< Tinh(n) << endl;

 return 0;