Author: Arindam Baidya
Tester: Chinmay Rakshit
Editorialist: Chinmay Rakshit
CAKEWALK, SIMPLE, EASY
MATH, MODULO FUNCTION
Suppose you have a round table and each member are placed around this round table and when a person places a proposal than all the person in the roundtable asks a question except adjacent person including him.
It’s a plane permutation question, suppose there are n persons and one person places proposal than n-3 persons places question so:
for 1 person n-3 questions
then for n persons n*(n-3) questions
but since there would be repetition so n*(n-3)/2 would be the result.
still there is a corner case:
AUTHOR’S AND TESTER’S SOLUTIONS:
Author’s solution can be found here.
Tester’s solution can be found here.