Pointer Manipulation Target: 15s
Track running surplus and total balance. Reset start when tank goes negative.
total = tank = start = 0
for i in range(len(gas)):
diff = gas[i] - cost[i]
total += diff
tank += diff
if tank < 0:
start = i + 1
tank = 0
return start if total >= 0 else -1Type it from memory. Go.