C / C++ / MFC

#include <stdio.h>

#define N 5

double summation(double g[], int size);

int main()
{
  double a[N] =
  {
    0.035679,
    0.079935,
    0.033320,
    0.042424,
    0.012387
  };

  double s[N];

  int i;
  for (i=0; i<N; ++i)
  {
    s[i] = a[i]*a[i];
  }

  printf("summation = %g\n", summation(s,N));
}

double summation(double g[], int size)
{
  int i;
  double sum =0.0;
  double c=0.0;
  for(i=0; i<size ;i++)
  {
    double y = g[i] -c;
    double t = sum + y;
    c = (t-sum) - y;
    sum = t;
  }
  return sum;
}

#include <cstdlib>
#include <cstdio>

float sumArrayElements(float array[], int numItems)
{
    int i;
    float result = 0;
    for (i=0; i<numItems; i++)
        result += array[i];
    return result;
}

int main ()
{
    float array1[5] = {10.2, 13.7, 14.8, 99.0, 0.0};
    float arraySum1 = sumArrayElements( array1, 5);
    printf("Array sum: %.2f\n",arraySum1);

    int i;

    float *array2;
    int dynamicCount1 = 5;
    array2 = (float*)malloc(dynamicCount1 * sizeof(float) );
    for (i=0; i<dynamicCount1; i++)
        array2[i] = (float)rand()/(float)(RAND_MAX);
    float arraySum2 = sumArrayElements( array2, dynamicCount1);
    free(array2);
    printf("Array sum: %.2f\n",arraySum2);


    int dynamicCount2 = 10;
    float *array3 = new float[dynamicCount2];
    for (i=0; i<dynamicCount2; i++)
        array3[i] = (float)rand()/(float)(RAND_MAX);
    for (i=0; i<dynamicCount1; i++)
        array3[i] = (float)rand()/(float)(RAND_MAX);
    float arraySum3 = sumArrayElements( array3, dynamicCount2);
    delete array3;
    printf("Array sum: %.2f\n",arraySum3);

    return 0;
}

srand(12345);
    float z=0.0;
    float a=0.2,y=0.0;
    int i;
    for(i=0;i<5;i++)
    {
        float b=((float)rand()/(float)(RAND_MAX))*a;
        printf("%f\n",b);

        z=z+b;
    }
    printf("summation:\n%f\n",z);

Andraw111 wrote:

I don't where should I put my Fortran question, so I put it here.

Maybe a std::shared_ptr can be helpful for you.

You can use it as follows:

#include <memory>

using namespace std;

class Person
{
    shared_ptr<Person> parent;
 
public:
    Person(shared_ptr<Person> p) {parent = p;}
 
};

void DoSomething(shared_ptr<Person> p)
{
    // Do something here
}

int main()
{
    shared_ptr<Person> grandfather = make_shared<Person>(nullptr);
    shared_ptr<Person> father = make_shared<Person>(grandfather);
    shared_ptr<Person> son = make_shared<Person>(father);

    DoSomething(father);

    return 0;
}

class Person
{
	shared_ptr<Person> parent;

public:
	Person(shared_ptr<Person> p){ parent = p; }

};

int main()
{
	auto grandfather(make_shared<Person>(nullptr));
	auto father(make_shared<Person>(grandfather));
	auto son(make_shared<Person>(father));

	// Do something here

	return 0;
}

void function1(Person p)
{
	// p is a copy
}

void function2(Person& p)
{
    // p is a reference to the object passed 
    // in as a parameter, not a copy
}