Leetcode 799. Champagne Tower

Given poured cups into the top of a triangular glass tower where each glass holds 1 cup and any excess splits equally to the two glasses below, determine how full the (query_row, query_glass) glass is after the flow settles. The algorithmic challenge is to propagate overflow down the triangle (Pascal-like distribution) efficiently up to the queried row (≤100) and cap each glass at 1.