I attempted to solve this problem E — Count Sequences 2 from the recent ABC. This was my submission, using my modint template. But it received WA on 45 testcases. Replacing my template with taking mod with % passed easily (submission). Is there a bug in my modint template? Please help me out, I can't figure out any mistake. The template is taken mostly from the-tourist/algo and atcoder library.
the unsigned int can fuck up the modulo if you under/over flow
The first submission wouldn't be correct with any
modintimplementation. Check diff between the two submissions.