make code more readable

make code more readable

Author: AdePhil

greedy_methods/gas_station.py

@@ -1,36 +1,63 @@
+from dataclasses import dataclass
+
 """
 Task:
 There are n gas stations along a circular route, where the amount of gas
-at the ith station is gas[i].
+at the ith station is gas_quantities[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.
+You have a car with an unlimited gas tank and it costs costs[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
+Given two integer arrays gas_quantities and costs, 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
 
 Reference: https://leetcode.com/problems/gas-station/description
 
 Implementation notes:
 First, check whether the total gas is enough to complete the journey. If not, return -1.
 However, if there is enough gas, it is guaranteed that there is a valid
 starting index to reach the end of the journey.
-Greedily calculate the net gain (gas - cost) at each station.
+Greedily calculate the net gain (gas_quantity - cost) at each station.
 If the net gain ever goes below 0 while iterating through the stations,
 start checking from the next station.
 
 """
 
 
-def can_complete_journey(gas: list[int], cost: list[int]) -> int:
+@dataclass
+class GasStation:
+    gas_quantity: int
+    cost: int
+
+
+def get_gas_stations(gas_quantities: list[int], costs: list[int]) -> list[GasStation]:
+    """
+    This function returns a list of gas stations.
+
+    Args:
+        gas_quantities [list]: Amount of gas available at each station
+        cost [list]: The cost of gas required to move from a station to the next
+
+    Returns:
+        gas_stations [list]: a list of gas stations
+    """
+    gas_stations = [
+        GasStation(gas_quantity, cost)
+        for (gas_quantity, cost) in zip(gas_quantities, costs)
+    ]
+    return gas_stations
+
+
+def can_complete_journey(gas_quantities: list[int], costs: list[int]) -> int:
     """
     This function returns the index from which to start the journey
     in order to reach the end.
 
     Args:
-        gas [list]: Amount of gas available at each station
+        gas_quantities [list]: Amount of gas available at each station
         cost [list]: The cost of gas required to move from a station to the next
 
     Returns:
@@ -43,16 +70,18 @@ def can_complete_journey(gas: list[int], cost: list[int]) -> int:
     -1
 
     """
-    total_gas = sum(gas)
-    total_cost = sum(cost)
+    total_gas = sum(gas_quantities)
+    total_cost = sum(costs)
 
     if total_gas < total_cost:
         return -1
 
     start = 0
     net = 0
-    for i in range(len(gas)):
-        net += gas[i] - cost[i]
+    gas_stations = get_gas_stations(gas_quantities, costs)
+
+    for i, gas_station in enumerate(gas_stations):
+        net += gas_station.gas_quantity - gas_station.cost
         if net < 0:
             start = i + 1
             net = 0