You are given an integer array g of length n, where g[i] (1 ≤ i ≤ n) represents the next station you must go to from station i. There are n stations, numbered from 1 to n. It is guaranteed that every station eventually reaches station 1. Define the cost of a station i as the number of steps required to reach station 1 starting from station i (cost[1] = 0, and for i > 1, cost[i] = 1 + cost[g[i]]). Return the sum of the costs of all stations. Example 1: Input: g = [1,1,2,3] Output: 6 Explanation: Station 1 → cost 0, Station 2 → cost 1, Station 3 → cost 2, Station 4 → cost 3. Total = 6. Example 2: Input: g = [3,1,2] Output: 3 Explanation: Station 1 → cost 0, Station 2 → cost 1, Station 3 → cost 2. Total = 3. Example 3: Input: g = [2,1,1] Output: 2 Explanation: Station 1 → cost 0, Station 2 → cost 1, Station 3 → cost 1. Total = 2.
