题目如下:
We are given a linked list with
head
as the first node. Let's number the nodes in the list:node_1, node_2, node_3, ...
etc.Each node may have a next larger value: for
node_i
,next_larger(node_i)
is thenode_j.val
such thatj > i
,node_j.val > node_i.val
, andj
is the smallest possible choice. If such aj
does not exist, the next larger value is0
.Return an array of integers
answer
, whereanswer[i] = next_larger(node_{i+1})
.Note that in the example inputs (not outputs) below, arrays such as
[2,1,5]
represent the serialization of a linked list with a head node value of 2, second node value of 1, and third node value of 5.Example 1:
Input: [2,1,5]
Output: [5,5,0]Example 2:
Input: [2,7,4,3,5]
Output: [7,0,5,5,0]Example 3:
Input: [1,7,5,1,9,2,5,1]
Output: [7,9,9,9,0,5,0,0]Note:
1 <= node.val <= 10^9
for each node in the linked list.- The given list has length in the range
[0, 10000]
.
解题思路:本题是找出离自己最近的大于自己的数,和以前做过的 【leetcode】84. Largest Rectangle in Histogram 非常相似,区别在于【leetcode】84. Largest Rectangle in Histogram 是找出最近的比自己小的数,但是原理是一样的。我的解法就是把链表转成list,然后参照【leetcode】84. Largest Rectangle in Histogram的解法。
代码如下:
# Definition for singly-linked list.
# class ListNode(object):
# def __init__(self, x):
# self.val = x
# self.next = None class Solution(object):
def nextLargerNodes(self, head):
"""
:type head: ListNode
:rtype: List[int]
"""
val = []
while head != None:
val.append(head.val)
head = head.next
res = [0] * len(val)
for i in range(len(val)-2,-1,-1):
next = i+1
while res[next] != 0 and val[i] >= val[next] :
next = res[next]
if val[i] >= val[next]:
res[i] = 0
else:
res[i] = next
#print res
for i in range(len(res)):
if res[i] == 0:
continue
res[i] = val[res[i]]
return res