Dev - C++ - Ayuda Con un Programa De suma de factoriales con recursividad

double suma(double n1){

	double fac,sum;

	if(n1==1){

	    return 1;

	}

	else {

	 	sum= (n1 + suma(n1-1));

	 	return sum;

	}

double suma(double n1){

	double fac,sum;

	if(n1==1){

	    return 1;

	}

	else {

	 	sum=n1*suma(n1-1);

	 	return fac;

	}

#include <iostream>

#include <cstdlib>

using namespace std;

void factorial(int,  long int &);

void suma(int, long int &);

void suma_factorial(int, long int &);

int main() {

  long int f = 1;

  factorial(5, f);

  cout<<f<<endl;

  long int sum = 0;

  suma(5, sum);

  cout<<sum<<endl;

  long int sum_fact = 0;

  suma_factorial(4, sum_fact);

  cout<<sum_fact<<endl;

  return EXIT_SUCCESS;

}

void factorial(int n, long int &fact) {

 if(n > 1) {

   fact *= n;

   factorial(n-1, fact);

 }

}

void suma(int n, long int &sum) {

  if(n>0) {

    sum += n;

    suma(n-1, sum);

  }

}

void suma_factorial(int n, long int &sum) {

  if(n >= 0) {

    long int fact = 1;

    factorial(n, fact);

    sum += fact;

    suma_factorial(n-1, sum);

  }

}