Code Chef january challenge unofficial editorial for first 5 problems

Rectangle:

This is the easiest problem of the contest. Opposite sides of a rectangle are equal. So use this property to see if there are 2 pairs of equal sides.

Longest increasing subsequence

Contents:

1. Wtf is Longest increasing subsequence?
2. Dynamic programming approach to find the length.
3. O(nlog(n)) solution to find length using binary search.