Package g0101_0200.s0134_gas_station

Class Solution

  • public class Solution
extends Object
    134 - Gas Station\. Medium There are `n` gas stations along a circular route, where the amount of gas at the ith station is `gas[i]`. You have a car with an unlimited gas tank and it costs `cost[i]` of gas to travel from the ith station to its next (i + 1)th station. You begin the journey with an empty tank at one of the gas stations. Given two integer arrays `gas` and `cost`, return _the starting gas station's index if you can travel around the circuit once in the clockwise direction, otherwise return_ `-1`. If there exists a solution, it is **guaranteed** to be **unique** **Example 1:** **Input:** gas = [1,2,3,4,5], cost = [3,4,5,1,2] **Output:** 3 **Explanation:** Start at station 3 (index 3) and fill up with 4 unit of gas. Your tank = 0 + 4 = 4 Travel to station 4. Your tank = 4 - 1 + 5 = 8 Travel to station 0. Your tank = 8 - 2 + 1 = 7 Travel to station 1. Your tank = 7 - 3 + 2 = 6 Travel to station 2. Your tank = 6 - 4 + 3 = 5 Travel to station 3. The cost is 5. Your gas is just enough to travel back to station 3. Therefore, return 3 as the starting index. **Example 2:** **Input:** gas = [2,3,4], cost = [3,4,3] **Output:** -1 **Explanation:** You can't start at station 0 or 1, as there is not enough gas to travel to the next station. Let's start at station 2 and fill up with 4 unit of gas. Your tank = 0 + 4 = 4 Travel to station 0. Your tank = 4 - 3 + 2 = 3 Travel to station 1. Your tank = 3 - 3 + 3 = 3 You cannot travel back to station 2, as it requires 4 unit of gas but you only have 3. Therefore, you can't travel around the circuit once no matter where you start. **Constraints:** * `gas.length == n` * `cost.length == n` * 1 <= n <= 105 * 0 <= gas[i], cost[i] <= 104

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • canCompleteCircuit

        public int canCompleteCircuit​(int[] gas,
                              int[] cost)