Clash of Coders CLCO04 - Editorial

PROBLEM LINK:

Practice

Contest

Author: Chahak Gupta

Tester: Rahul Johari

DIFFICULTY:

EASY.

PREREQUISITES:

Sorting

EXPLANATION:

Note that the number of unlucky tiles ≤ 3000. Chahak can reach tile number n if the first and the last tiles are not unlucky and there are not three or more unlucky tiles in a row. So let sort the array of unlucky tiles and go through it, checking for three or more consecutive unlucky tiles. Also one needs to check if the first or the last tile is in this array are lucky.

AUTHOR’S AND TESTER’S SOLUTIONS:

Author’s solution can be found here.