Added gas_station.py

data_structures/arrays/gas_station.py

@@ -0,0 +1,42 @@
+class Solution:
+    def can_omplete_circuit(self, gas: list[int], cost: list[int]) -> int:
+        """
+        Finds the starting station index to complete the circuit,
+        or returns -1 if not possible.
+        Args:
+        gas (List[int]): List of gas available at each station.
+        cost (List[int]): List of gas costs to travel to the next station.
+        Returns:
+        int: The index of the starting station, or -1 if no solution exists.
+        Examples:
+        >>> solution = Solution()
+        >>> solution.can_omplete_circuit([1, 2, 3, 4, 5], [3, 4, 5, 1, 2])
+        3
+        >>> solution.can_omplete_circuit([2, 3, 4], [3, 4, 3])
+        -1
+        >>> solution.can_omplete_circuit([5, 1, 2, 3, 4], [4, 4, 1, 5, 1])
+        4
+        """
+        total_gas = 0
+        current_gas = 0
+        start_station = 0
+
+        for i in range(len(gas)):
+            total_gas += gas[i] - cost[i]
+            current_gas += gas[i] - cost[i]
+
+            if current_gas < 0:
+                start_station = i + 1
+                current_gas = 0
+
+        if total_gas < 0:
+            return -1
+        else:
+            return start_station
+
+
+# Example usage with doctests
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()