Always love @vijju123’s editorials. Especially the related problems part and the extra parts that he includes!

# CHFDORA - Editorial

If you write the second statement in your code i.e. `while(A[i]%2==0 and i < n) ++i;`

As **Logical AND** (\&\&) is a sequence point (Sequence point is a point in your instruction which makes sure that all the instructions written before it must be evaluated first and any side-effect must be complete) the expression A[i] % 2 == 0 will be evaluated first.

Now if the value of `i`

is \geq n then it is the case of Segmentation Fault and your program will generate **SIGSEGV** Error.

Thanks for Reading

Peace

I am sure if my solution is fast enough than other optimized solutions will be much more faster.

I think you can try increasing N*M to 5*10^5 or 10^6. Not sure though.

yeah i did the same thing and still got tle can someone explain why?

@vijju123 when can we expect the editorials of the challenge problems? and also of Army of me? Eagerly waiting for the editorial of Army of me

Very Good editorial!

what does this line mean…

given constraints are:

- 1≤T≤1001≤T≤100
- 1≤N,M1≤N,M
- N⋅M≤105N⋅M≤105
- 1≤Ai,j≤1061≤Ai,j≤106 for each valid i,ji,j
- the sum of N⋅MN⋅M over all test cases does not exceed 3⋅105

Why were 100 points awarded for the Brute force implementation? I feel that 100 pts should have been awarded for the O(N*M) approach using Manacher’s algorithm.

https://www.codechef.com/viewsolution/28964203

can some one tell why i am getiing TLE for three test cases for my solution and all other test cases are okay

can you please explain why min(N,M)<350 ?

thanks!

Because if min(n, m) > 350 then the condition n * m < 10^5 would not hold because 350 * 350 > 10 ^ 5 .

Read the editorial further and know more. I hope you know that clicking on those Arrow like things will reveal more content.

https://www.codechef.com/viewsolution/29115055

I have implemented the same logic, still I’m getting WA in some testcases.

Please help

This is how I did in Java

```
public static void main (String[]args) throws java.lang.Exception
{
// your code goes here
Reader in = new Reader();
int t = in.nextInt ();
for (int i = 0; i < t; i++)
{
int r=in.nextInt();
int c=in.nextInt();
int[][] a=new int[r][c];
for (int j=0;j<r;j++)
{
for (int k=0;k<c;k++)
{
a[j][k]=in.nextInt();
}
}
int count=r*c;
int ud=0;
int lr=0;
for (int j=1;j<r-1;j++)
{
if (j<r-j-1)
{
ud=j;
}
else
{
ud=r-j-1;
}
for (int k=1;k<c-1;k++)
{
if (k<c-k-1)
{
lr=k;
}
else
{
lr=c-k-1;
}
for (int q=1;q<=ud && q<=lr; q++)
{
if (a[j][k-q]==a[j][k+q] && a[j-q][k]==a[j+q][k])
{
count++;
}
else break;
}
}
}
System.out.println(count);
}
```

I just remembered, my nm(n+m) program passed with 0.03 seconds, just by auto coding the answer when an entire row is the same.

https://www.codechef.com/viewsolution/28704770

DONT PASTE CODE HERE