please help in debugging the code its giving the correct answer for test cases I check for please help it is the problem from sept long challenge 2019

question :long challenge sept icin

my code:https://www.codechef.com/viewsolution/26585210

Yours seems to work for small testcases, but fails for larger ones - overflow is the most likely.

This line is suspicious:

```
mount=b*(d-b)*(c-b)+mount;
```

1 Like

Good point by @ssjgz . The other thing that you can keep in mind is whenever there are any subtractions during MOD, the result might become negative and C++ might return a negative mod. So at the end, you might have to do this:

if (mount < 0) {mount += MOD;}

3 Likes

that for when both values of a and c are grater than b than we can easily multiply the ranges so I calculated Them in the starting

for eg . A=100,B=50,C=100

then for values of a>50 and c>50 can pair up with any value of c thus there are total

50*50*B values

exactly where I m very curious why I m getting wA in the end