arrays_task_18.cpp

#include <iostream>

using namespace std;

int main()
{
	const int size = 10;
	float a[size];
	
	for(int i = 0; i < size; i++)
	{
		cin >> a[i];
	}
	
	for(int i = 0; i < size; i++)
	{	
		if(int(a[i]) % 4 == 0)
		{
			if(i < 3)
				continue;	
			
			a[i] = (a[i-1]+a[i-2]+a[i-3])/3;	
		}	
	}
	
	for(int i = 0; i < size; i++)
	{
		cout << a[i] << endl;
	}
	
	return 0;
}

arrays_task_3.cpp

#include <iostream>

using namespace std;

int main()
{
	const int size = 8;
	int a[size], b[size], c[size], d[3*size];
	
	for(int i = 0; i < size*3; i++)
	{
		if(i < size)
		{
			cin >> a[i]; 
		}
		else if(i < size*2)
		{
			cin >> b[i - size];
		}
		else
		{
			cin >> c[i- (size * 2)];
		}
	}
	
	for(int i = 0; i < size; i++)
	{
		cout << a[i] << " ";
		cout << b[i] << " ";
		cout << c[i] << " ";
	}
	
	return 0;
}

arrays_task_4.cpp

#include <iostream>

using namespace std;

int main()
{
	const int size = 5;
	
	int a[size], b[size], k, ff1 = 0, ff2 = 0;
	
	for(int i = 0; i < size*2; i++)
	{
		cin >> k;
		
		if(k >= 0)
		{
			a[ff1] = k;
			ff1++;
		}
		else
		{
			b[ff2] = k;
			ff2++;
		}
	}
	
	for(int i = 0; i < size; i++)
	{
			cout << a[i] << " ";
			cout << b[i] << " ";
	}	
	
	return 0;
}

arrays_task_6.cpp

#include <iostream>

using namespace std;

int main()
{
	const int size = 10;
	int x, index = -1, product = 1, sum = 0;
	
	for(int i = 0; i < size; i++)
	{
		cin >> x;
		
		if(x == 0 && index == -1)
		{
			index = x;
			continue;
		}
		
		if(index == -1)
			product *= x;
		
		if(i > index && index != -1)
			sum += x;
		
	}
	
	cout << "Product before 0 = " << product << endl;
	cout << "Sum after 0 = " << sum << endl;
	
	return 0;
}