Count Gift Pairs with Exponential Sum

You are given an array where each number represents the price of a gift. If the sum of the prices of two gifts equals 3 raised to some power, then a 50% discount is applied. Return the total number of such pairs that can be found. Input: An integer array prices, representing the price of each gift. Output: An integer, representing the number of pairs found. Example: Input: prices = [1, 2, 3, 9] Output: 1 Explanation: You can find one pair (1, 2) such that 1 + 2 = 3^1 = 3. Constraints: 1 <= prices.length <= 10^5 0 <= prices[i] <= 10^9 Example Input 1 2 3 9