problem witth sum of elements in array with recursion

[mpg]

I must do the sum of elements in arry with recursion and I must use codeblocks.
I have "cannot open output file, name.exe permission denied"
What's problem?

  
#include <cstdlib>
#include <ctime>
#include <cmath>
#include <iostream>

using namespace std;

int somma(int A[], int n)
{if (n=0)
return 0;
else
return A[n] + somma (A, n-1);
}

int main()
{
int n;
cin>>n;
int A[n];
cin>>A[n];
cout<<somma(A, n);
}
 

[Repeater]

Problem is nothing to do with your code.

Problem is you are still running the program you made. Stop running it.

[salem c]

But there are lots of issues with the code.
> {if (n=0)
Using = where you should be using ==

> return A[n] + somma (A, n-1);
A[n] is an out-of-bound memory access, based on your initial call in main.

> int A[n];
This isn't valid C++, since variable length arrays are not supported.

> cin>>A[n];
This is an out of bound memory access as well.
Also, it does NOT automatically read in n integers and populate the array for you.

[mpg]

Excuse me salem but I don't understand well the problem

  
#include <cstdlib>
#include <ctime>
#include <cmath>
#include <iostream>

using namespace std;

int somma(int A[], int n)
{if (n==0)
return 0;
else
return A[n] + somma (A, n-1);
}

int main()
{
int n;
cin>>n;
int A[n];
cin>>A[n];
cout<<somma(A, n);
}
 

probably so is right

#include <cstdlib>
#include <ctime>
#include <cmath>
#include <iostream>

using namespace std;


int somma(int A[], int n)
{if (n==0)
return 0;
else
return A[n-1] + somma (A, n-1);
}

int main()
{

int A[5] = {1, 2, 3, 4, 5};
int n=5;
cout<<somma(A, n);
}

[salem c]

Well your 2nd one looks good.

But the first one needs a loop if you want to input N integers.

[mpg]

I can't understand this kind of loop...

is it right?

#include <cstdlib>
#include <ctime>
#include <cmath>
#include <iostream>

using namespace std;


int somma(int A[], int n)
{if (n==0)
return 0;
else
return A[n-1] + somma (A, n-1);
}

int main()
{

  int n=7;
  int A[n];
  for(int i=0; i<n; i++)
  {
    cin>>A[i];
  }

cout<<somma(A, n);
}

[mpg]

With this I must search if all the numbers of array are greatest then 10.... but I have problems.. always with recursion (and bool).

#include <cstdlib>

#include <ctime>

#include <cmath>

#include <iostream>


using namespace std;



bool tutti(int A[], int n)

{if (n<=10)

  return false;

else

return tutti (A,n-1);

}


int main()

{

int A[6] = {11, 21, 101, 41, 51,61};

int n=6;


cout<<tutti(A, n);

}

[salem c]

> if (n<=10)
You need to be comparing each A[n] with 10.
Not checking to see if you have less than 10 elements left in your array.

> With this I must search the number greatest then 10
You should try to solve the problem using a loop first.
If for no other reason, to make sure you actually understand the problem.

[mpg]

Always result 0..

#include <cstdlib>

#include <ctime>

#include <cmath>

#include <iostream>


using namespace std;


bool tutti(int A[], int n)

{

  if (A[n]<=10)

    return false;

  else

    return tutti (A,n-1);

}


int main()

{

  int A[6] = {11, 21, 101, 41, 51,61};

  int n=6;

  cout<<tutti(A, n);

}

[salem c]

You're supposed to check ALL the elements of the array.

Not bail out completely when the first element less than 10 is found.

Again, try and write it as a simple loop BEFORE you try and make it recursive.

Typing in random recursive code won't get you anywhere until you actually understand the problem.

[anup30]

2nd problem

#include <iostream>
using namespace std;

bool tutti(int ar[], int size){
	if(size==0) return true;
	if(ar[size-1]<=10) return false;
	tutti(ar, size-1);
}

int main(){
	int aa[5] ={12,14,16,18,20};
	int ab[5] ={12,14,16,8,20};
	
	cout << tutti(aa,5)<< endl;
	cout << tutti(ab,5)<< endl;
}

[mpg]

Thanks!!!!