gas_station.json

{
    "problem_name": "gas_station",
    "solution_class_name": "Solution",
    "problem_number": "134",
    "problem_title": "Gas Station",
    "difficulty": "Medium",
    "topics": "Array, Greedy",
    "readme_description": "There are `n` gas stations along a circular route, where the amount of gas at the `ith` station is `gas[i]`.\n\nYou 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.\n\nGiven 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**.",
    "_readme_examples": {
        "list": [
            {
                "content": "```\nInput: gas = [1,2,3,4,5], cost = [3,4,5,1,2]\nOutput: 3\nExplanation:\nStart at station 3 (index 3) and fill up with 4 unit of gas. Your tank = 0 + 4 = 4\nTravel to station 4. Your tank = 4 - 1 + 5 = 8\nTravel to station 0. Your tank = 8 - 2 + 1 = 7\nTravel to station 1. Your tank = 7 - 3 + 2 = 6\nTravel to station 2. Your tank = 6 - 4 + 3 = 5\nTravel to station 3. The cost is 5. Your gas is just enough to travel back to station 3.\nTherefore, return 3 as the starting index.\n```"
            },
            {
                "content": "```\nInput: gas = [2,3,4], cost = [3,4,3]\nOutput: -1\nExplanation:\nYou can't start at station 0 or 1, as there is not enough gas to travel to the next station.\nLet's start at station 2 and fill up with 4 unit of gas. Your tank = 0 + 4 = 4\nTravel to station 0. Your tank = 4 - 3 + 2 = 3\nTravel to station 1. Your tank = 3 - 3 + 3 = 3\nYou cannot travel back to station 2, as it requires 4 unit of gas but you only have 3.\nTherefore, you can't travel around the circuit once no matter where you start.\n```"
            }
        ]
    },
    "readme_constraints": "- `n == gas.length == cost.length`\n- `1 <= n <= 10^5`\n- `0 <= gas[i], cost[i] <= 10^4`\n- The input is generated such that the answer is unique.",
    "helpers_imports": "",
    "helpers_content": "",
    "helpers_run_name": "can_complete_circuit",
    "helpers_run_signature": "(solution_class: type, gas: list[int], cost: list[int])",
    "helpers_run_body": "    implementation = solution_class()\n    return implementation.can_complete_circuit(gas, cost)",
    "helpers_assert_name": "can_complete_circuit",
    "helpers_assert_signature": "(result: int, expected: int) -> bool",
    "helpers_assert_body": "    assert result == expected\n    return True",
    "solution_imports": "",
    "solution_contents": "",
    "solution_class_content": "",
    "test_imports": "import pytest\nfrom leetcode_py import logged_test\nfrom .helpers import assert_can_complete_circuit, run_can_complete_circuit\nfrom .solution import Solution",
    "test_content": "",
    "test_class_name": "GasStation",
    "test_class_content": "    def setup_method(self):\n        self.solution = Solution()",
    "_solution_methods": {
        "list": [
            {
                "name": "can_complete_circuit",
                "signature": "(self, gas: list[int], cost: list[int]) -> int",
                "body": "        # TODO: Implement can_complete_circuit\n        return -1"
            }
        ]
    },
    "_test_helper_methods": {
        "list": [{ "name": "setup_method", "parameters": "", "body": "self.solution = Solution()" }]
    },
    "_test_methods": {
        "list": [
            {
                "name": "test_can_complete_circuit",
                "signature": "(self, gas: list[int], cost: list[int], expected: int)",
                "parametrize": "gas, cost, expected",
                "test_cases": "[([1,2,3,4,5], [3,4,5,1,2], 3), ([2,3,4], [3,4,3], -1), ([1,2], [2,1], 1), ([5], [4], 0), ([2], [2], 0), ([1,2,3], [3,3,3], -1), ([3,1,1], [1,2,2], 0), ([5,1,2,3,4], [4,4,1,5,1], 4), ([1,2,3,4,5,5,70], [2,3,4,3,9,6,2], 6), ([4,5,2,6,5,3], [3,2,7,3,2,9], -1), ([6,1,4,3,5], [3,8,2,4,2], 2), ([2,3,4,5], [3,4,5,6], -1)]",
                "body": "        result = run_can_complete_circuit(Solution, gas, cost)\n        assert_can_complete_circuit(result, expected)"
            }
        ]
    },
    "playground_imports": "from helpers import run_can_complete_circuit, assert_can_complete_circuit\nfrom solution import Solution",
    "playground_setup": "# Example test case\ngas = [1,2,3,4,5]\ncost = [3,4,5,1,2]\nexpected = 3",
    "playground_run": "result = run_can_complete_circuit(Solution, gas, cost)\nresult",
    "playground_assert": "assert_can_complete_circuit(result, expected)"
}