Given two integer arrays fuel_supply and travel_cost, each of length n, representing the amount of fuel available at each station and the cost to travel to the next station in a circular route, determine the starting station index from which a complete circuit can be made. If no such starting index exists, return -1. The solution is guaranteed to be unique if it exists.
Example 1
Input: fuel_supply = [4, 6, 7, 3], travel_cost = [6, 5, 3, 5]
Output: 1
Explanation: Starting at index 1, you can complete the circuit.
Example 2
Input: fuel_supply = [5, 1, 2, 3, 4], travel_cost = [4, 4, 1, 5, 1]
Output: 4
Explanation: Starting at index 4, you can complete the circuit.
Example 3
Input: fuel_supply = [2, 2, 2], travel_cost = [3, 3, 3]
Output: -1
Explanation: No starting index allows completing the circuit.
Constraints
Case 1
Input: fuel_supply = [3, 1, 2, 5, 4], travel_cost = [2, 2, 2, 2, 2]
Expected: 3
Case 2
Input: fuel_supply = [1, 2, 3, 4], travel_cost = [2, 2, 2, 2]
Expected: 2
Case 3
Input: fuel_supply = [7, 1, 0, 11, 2], travel_cost = [5, 2, 3, 4, 6]
Expected: 3
Case 4
Input: fuel_supply = [0, 0, 0], travel_cost = [0, 0, 0]
Expected: 0
Case 5
Input: fuel_supply = [10, 0, 0, 0], travel_cost = [1, 1, 1, 8]
Expected: 0