Finds the maximal sequence

Write a program, which finds the maximal sequence of consecutively placed increasing integers. Example: {3, 2, 3, 4, 2, 2, 4} ? {2, 3, 4}.

I write this program but when i enter n=5 and 2 5 6 7 6 isn't work :(
i'm beginner in c# so...

Sorry for my bad english i am Romanian

static void Main()
{
Console.Write("n=");
int n = int.Parse(Console.ReadLine());
int[] a = new int [n];
for (int i = 0; i < n; i++)
{
Console.Write("a[{0}]=", i);
a[i] = int.Parse(Console.ReadLine());
}
Console.WriteLine("maximal sequence");
for (int i = 0; i < n; i++)
{
for (int j = i + 1; j < n; j++)
{
if (a[i] {
Console.WriteLine(a[i]);
break;
}

}

}

}

I assume that by 'maximal' sequence you mean the sequence with the longest length and that, when you say that consecutively placed integers are increasing you don't necessarily mean that they increase by one each time.

So. if you have {1, 2, 4, 3, 2, 3, 7, 9} then the maximal sequence will be {2, 3, 7, 9} because it's longer than {1, 2, 4}.

I've further assumed that if there is more than one maximal sequence, then the first one will be returned. So, if you have, {8, 9, 10, 7, 1, 2, 3} then the maximal sequence returned will be {8, 9, 10} rather than {1, 2, 3} because it's the first one in the array.

On that basis, the following should work:

using System;

class Program

{

static void Main()

{

Console.Write("n=");

int n = int.Parse(Console.ReadLine());

if (n < 1)

{

Console.WriteLine("Can't be less than 1 integer");

return;

}

int[] a = new int [n];

for (int i = 0; i < n; i++)

{

Console.Write("a[{0}]=", i);

a[i] = int.Parse(Console.ReadLine());

}

int start = 0, end = 0;

int maxStart = 0, maxEnd = 0;

int len = 1;

int maxLen = 1;

while(end < n - 1)

{

end++;

if (a[end] <= a[end - 1])

{

len = end - start;

if (len > maxLen)

{

maxStart = start;

maxEnd = end - 1;

maxLen = len;

}

start = end;

}

else if ((a[end] > a[end - 1]) && (end == n - 1))

{

len = end - start + 1;

if (len > maxLen)

{

maxStart = start;

maxEnd = end;

maxLen = len;

}

Console.WriteLine("maximal consecutively placed increasing sequence (length = {0})", maxLen);

for (int i = maxStart; i <= maxEnd; i++)

{

Console.WriteLine("a[{0}]={1}", i, a[i]);

}

Console.ReadKey();

}

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Vulpes11y ago
I assume that by 'maximal' sequence you mean the sequence with the longest length and that, when you say that consecutively placed integers are increasing you don't necessarily mean that they increase by one each time.

So. if you have {1, 2, 4, 3, 2, 3, 7, 9} then the maximal sequence will be {2, 3, 7, 9} because it's longer than {1, 2, 4}.

I've further assumed that if there is more than one maximal sequence, then the first one will be returned. So, if you have, {8, 9, 10, 7, 1, 2, 3} then the maximal sequence returned will be {8, 9, 10} rather than {1, 2, 3} because it's the first one in the array.

On that basis, the following should work:

using System;

class Program
{
static void Main()
{
Console.Write("n=");
int n = int.Parse(Console.ReadLine());

if (n < 1)
{
Console.WriteLine("Can't be less than 1 integer");
return;
}

int[] a = new int [n];

for (int i = 0; i < n; i++)
{
Console.Write("a[{0}]=", i);
a[i] = int.Parse(Console.ReadLine());
}

int start = 0, end = 0;
int maxStart = 0, maxEnd = 0;
int len = 1;
int maxLen = 1;

while(end < n - 1)
{
end++;
if (a[end] <= a[end - 1])
{
len = end - start;

if (len > maxLen)
{
maxStart = start;
maxEnd = end - 1;
maxLen = len;
}

start = end;
}
else if ((a[end] > a[end - 1]) && (end == n - 1))
{
len = end - start + 1;

if (len > maxLen)
{
maxStart = start;
maxEnd = end;
maxLen = len;
}
}
}

Console.WriteLine("maximal consecutively placed increasing sequence (length = {0})", maxLen);

for (int i = maxStart; i <= maxEnd; i++)
{
Console.WriteLine("a[{0}]={1}", i, a[i]);
}

Console.ReadKey();
}
}