python - Car Fueling by greedy algorithm failing

Question

Problem Introduction You are going to travel to another city that is located d miles away from your home city. Your car can travel at most m miles on a full tank and you start with a full tank. Along your way, there are gas stations at distances stop 1 , stop 2 , . . . , stop n from your home city. What is the minimum number of refills needed?

my code is running fine on my machine but the grader fails at some point and it does not tell me why so i can correct it

def compute_min_refills(distance, tank,n, stops):
count=0
start = 0
stops.append(distance)
for i in range(len(stops)):
    if distance > tank+ start:
        if tank + stops[i-1] < stops[i]:
            return -1
        if tank < stops[i]:
            start = stops[i-1]
            count += 1


return count

if __name__ == '__main__':
d, m, n, *stops = map(int, sys.stdin.read().split())
print(compute_min_refills(d, m, n, stops))

Answer 1

等待大神答复