Champagne Tower Overflow Amount Calculation

bytedance We have a triangle-shaped wine tower where the first row has 1 glass, the second row has 2 glasses, and so on. The glasses are arranged such that they overflow evenly, where the overflowed champagne gets equally distributed between the glasses in the next row. You pour champagne into the topmost glass. After pouring, you need to determine the amount of champagne in a specific glass at a certain row. Each glass can hold one cup of champagne. Write a function that takes the poured champagne units, the query row, and the target glass index in that row and returns how much champagne is in that glass. Example Input 25 3 2