Gas Station

Problem: Gas Station There are n gas stations arranged in a circle. The i-th station contains gas[i] units of gas. You have a car with an unlimited gas tank. Traveling from station i to station i + 1 costs cost[i] units of gas. The car starts with an empty tank. Determine whether there exists a starting station such that the car can travel around the circuit exactly once. Return the starting station index if possible; otherwise return -1. It is guaranteed that if a solution exists, it is unique. Input Format n gas[0] gas[1] ... gas[n-1] cost[0] cost[1] ... cost[n-1] Output Format start_index Constraints 1 <= n <= 10^5 0 <= gas[i], cost[i] <= 10^4 Example Input: 5 1 2 3 4 5 3 4 5 1 2 Output: 3 Example Input 5 1 2 3 4 5 3 4 5 1 2 Output 3