plz help why my code given wrong answer,???

#include <bits/stdc++.h>

using namespace std;

int main()

{

ios_base::sync_with_stdio(false);

cin.tie(0);

int t;cin>>t;

while(t–)

{

unsigned long long n,k,ans;

cin>>n>>k;

if(k%2==0)

{

ans=(n+((k/2)-1))*(n+(k/2))+n;*

}

else

{

ans=(n+(k/2))(n+(k/2)+1)-n;

}

cout<<ans<<endl;

}

return 0;

}

you are not taking modulo at any step. This is one of the mistake

but test case given right answer,

plz help i can’t understand i can i use that in this case

for n=0. this won’t work.

Which test case, the sample? Of course modulo wouldn’t affect that, the answers are nowhere near 1 billion.

Here’s a case you’ll fail on:

```
1
1000000000 1000000000
```

expected answer: `750000119`

Also, format your code or link the submission, because it’s literally impossible for us to debug it otherwise.

Ok but for large number like n = 10^9 and k = 10^9 it would result in very large number and integer overflow so what you need is do modulo **m** which will be given in question.

see this CodeChef: Practical coding for everyone