Today(the 24th of April) is the 107th anniversary of armenian genocide.

Hi Codeforces Community!

Can anyone tell please what this expression (n & (-n)) returns?

Hi, Codeforces community!

I tried to solve this problem by using recursion. But my submission gives wrong answer to test 5. The input is: 20 293434130 567534945 339132630 291152695 959629878 416618095 149341899 479358017 509348379 335313693 386003521 360528367 387150541 724271523 741417449 63831275 308645820 457460287 716709394 977143845. The answer is 5734409263, but my code's output is 5774922309. Can anyone tell where's the mistake please?

Hi, Codeforces Community!

I recently looked to a programm written by a participant in the contest, and I noticed this function, which is finding the greatest common devisor of two numbers.

long long int gcd(long long int a, long long int b) { return (b == 0LL ? a : gcd(b, a % b)); }

But I don't understand how this part (b == 0LL ? a : gcd(b, a % b)) of the function is working. Can anyone explain please?

I participated in contest, and I found this problem really interesting. But, unfortunately, I couldn't solve that. Can you tell me what algorithm should I use please?