Can anyone tell me what is the wrong with my code??
first we calculate those no. who have no follow pp-qq condition then to find the answer total - count
/* package codechef; // don’t place package name! */
import java.util.;
import java.lang.;
import java.io.*;
/* Name of the class has to be “Main” only if the class is public. */
class Codechef
{
public static void main (String[] args) throws java.lang.Exception
{
Scanner sc=new Scanner(System.in);
int t=sc.nextInt();
int count=0;
while(t>0)
{
int n=sc.nextInt();
int[] arr=new int[n];
for(int j=0;j<n;j++)
{
arr[j]=sc.nextInt();
}
for(int i=0;i<n;i++)
{
int temp=1;
for(int j=i;j<n;j++)
{
temp=temp Math.abs(arr[j]);
if(temp%4==2)
{
count++;
}
}
temp=1;
}
int ans=(n(n+1)/2)-count;
System.out.println(ans);
count=0;
ans=0;
t–;
}
}
}
Whats HAPPENING IN THIS PROBLEM ?
got it…it was also integer overflow error…i was taking n as int and then calculating n*(n+1)/2
temp%4!=0 in case of temp%4==0
bro i m not able to understand your code or your approach …why so much complex approach when u can solve this in very easy manner
i have done the same mistake. take n as input and calculate n*(n+1)/2 which can be greater than int.
that is the problem. just take n as long
1 Like
Overflow 
Might come as a surprise but even python has a limit. Its around 10^{7000} or something for value of variables. Once you cross this, you get a runtime error.
3 Likes
Code 1
if (a[i] % 2 == 0)
a[i] = 1
else
a[i] = 0
Code 2
if (a[i] % 2 == 1)
a[i] = 0
else
a[i] = 1
I used Code 1 and I had AC but I used Code 2 and had WA. I’m trying to understand why. Any idea?
Thank you for the info Sir @vijju123
can anyone where I am getting wrong ,I tried a brute force approach to the problem and its giving correct outputs as per me .Link to the code is below,please help and thanks.
https://www.codechef.com/viewsolution/31680208
I did the same but it get wrong answer in two cases… Please review it… Thanks… CodeChef: Practical coding for everyone
Could you please explain it a bit more ? Why sum = 1 works ?
2,6,10,14,18,22… this is series they all no. are do not give the pp-qq result.
so all they no. if we identify then we see that all no. are devided by 4 remainder ==2
2%4==2
6%4==2
10%4==2
so why we need to calculate temp%4==0 or temp%4!=0
1 Like
Does that mean If sum = 1 then the product has only one 2 in prime factor. And that’s why It doesn’t count
How can it be N*logN?
Please help?
And how will O(N) pass the test cases?
the constraints specify that
N over all test cases does not exceed 10^6
and there are 10^3 tests cases
then for O(N) there are 10^3 * 10^6 = 10^9 operations
how will O(N ) pass the test cases?
squared subsequence
i tried to implement the editorial solution but getting only partial marks and cant seem to figure out why?
Can anyone please help?
@ssrivastava90 I followed exactly the same approach but my code is failing in 2 tasks. Please check if you could fix out the bug . Any help is welcomed.