You are given a 2D array of integers, envelopes, where each element envelopes[i] = [wi, hi] represents the width and height of an envelope. An envelope can fit inside another if and only if its width and height are strictly smaller than the width and height of the other envelope. The task is to determine the maximum number of envelopes that can be nested inside each other, similar to Russian dollsRussian dolls, also known as stacking dolls or nesting dolls, are a set of wooden dolls of decreasing size placed one inside another. .

Constraints:

• $1\leq$ envelopes.length $\leq 10^3$

• envelopes[i].length $== 2$

• $1\leq$ wi, hi $\leq 10^4$

This solution uses a combination of sorting and searching techniques to determine the maximum number of envelopes that can be nested within each other, keeping in light that both the width and height of the envelope to fit must be smaller than the other envelope. The challenge in this problem is to simultaneously compare dimensions, width, and height while keeping the solution right. This is handled by sorting the envelopes by width in ascending order and, in the case of ties, sorting by height in descending order. This descending height is important because it prevents misunderstanding of envelopes with the same width. ...