8.12笔记

近期都是回顾一下以前做过的题：

134. 加油站

class Solution(object):
    def canCompleteCircuit(self, gas, cost):
        """
        :type gas: List[int]
        :type cost: List[int]
        :rtype: int
        """
        start,end,res = 0,0,0
        for i in range(len(gas)):
            start += gas[i] - cost[i]
            end += gas[i] - cost[i]
            if start < 0:
                res = i+1
                start = 0
        return -1 if end < 0 else res

328. 奇偶链表

class Solution(object):
    def oddEvenList(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        l1 = odd = ListNode(0)
        l2 = even = ListNode(0)
        while head:
            l1.next = head
            l2.next = head.next
            l1 = l1.next
            l2 = l2.next
            head = head.next.next if l2 else None
        l1.next = even.next
        return odd.next