Tính S(x, n) = -x + x^2/(1 + 2) – x^3/(1 + 2 + 3) + … + (-1)^n * x^n/(1 + 2 +… + n)

#include<stdio.h>
#include<conio.h>
#include<math.h>
int main()
{
	int i, n;
	float x, S, T;
	long M;
	printf("\nNhap x: ");
	scanf("%f", &x);
	do
	{
	printf("\nNhap n: ");
	scanf("%d", &n);
	  if(n < 1)
	  {
		  printf("\n N phai >= 1. Xin nhap lai !");
	  }

	}while(n < 1);

	S = 0;
	T = 1;
	M = 0;
	i = 1;

	while(i <= n)
	{
		T = T * x;
		M = M + i;
		S = S + pow(-1, (float)i) * T/M;
		i++;
	}
	printf("\nTong la %f", S);
	getch();
	return 0;
}