Fix 0134-gas-station.py

Author: sickerin

python/0134-gas-station.py

@@ -1,14 +1,15 @@
 class Solution:
     def canCompleteCircuit(self, gas: List[int], cost: List[int]) -> int:
-        start, end = len(gas) - 1, 0
-        total = gas[start] - cost[start]
+        if sum(gas) < sum(cost):
+            return -1
+            
+        total = 0
+        res = 0
+        for i in range(len(gas)):
+            total += (gas[i] - cost[i])
 
-        while start >= end:
-            while total < 0 and start >= end:
-                start -= 1
-                total += gas[start] - cost[start]
-            if start == end:
-                return start
-            total += gas[end] - cost[end]
-            end += 1
-        return -1
+            if total < 0:
+                total = 0
+                res = i + 1
+
+        return res