how can i get the longest sequence of increasing numbers from a vector in c++?

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I have this sequence of numbers stored in a vector: 4 7 2 6 5 1 3.
In this case, the longest sequence will be: 1,3,4,7. That’s 4 numbers.
I only need to get the value of the longest increasing sequence(in this case 4).

I have this code:


using namespace std;
ifstream f("roboti2.in");
ofstream g("roboti2.out");

int main()
{
    int cerinta, n;
    int v[10000];
    f>>cerinta>>n;

    if(cerinta==1)
    {
        int l=1;
        int maxl = 1;
        for(int i=0; i<=n;i++)
        {
            f>>v[i];
        }
        for(int i=1; i<=n; i++)
        {
            if(v[i] > v[i-1])
            {
               l++;
               if (l > maxl)
               {
                   maxl = l;
               }

            }
            else
            {
               l=1;
            }
        }
        g<<maxl;

    }
    return 0;
}

But it shows that it’s 2. It does not take the numbers at the end(1, 3) and 4,7.

Thanks!

>Solution :

To consider this kind of warp from the end to the beginning, an easy way is duplicating the array after the original array and also check the second array.

for(int i=0; i<=n;i++)
{
    f>>v[i];
}
// add this to duplicate the array
// (assuming v[0] .. v[n] is what to consider
for(int i=0; i<=n; i++)
{
    v[n+i+1] = v[i];
}
n += n + 1;

The size of array v should be increased to store the duplicate part if needed.

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