标签归档：leetcode

题目描述：

Sort a linked list using insertion sort.

题目大意：

使用插入排序对链表排序。

Python代码：

朴素版本（ Accepted 2568ms )：

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    # @param head, a ListNode
    # @return a ListNode
    def ...

题目描述：

Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST.

Calling next() will return the next smallest number in the BST.

Note: next() and hasNext() should run in ...

题目描述：

Given an integer n, return the number of trailing zeroes in n!.

Note: Your solution should be in polynomial time complexity.

题目大意：

给定一个整数n，返回n!（n的阶乘）数字中的后缀0的个数。

注意：你的解法应该满足多项式时间复杂度。

解题思路：

参考博文：http://www.geeksforgeeks.org/count-trailing-zeroes-factorial-number/

朴素解法：

首先求出n!，然后计算末尾0的个数。（重复÷10 ...

题目描述：

Related to question Excel Sheet Column Title

Given a column title as appear in an Excel sheet, return its corresponding column number.

For example:

    A -> 1
    B -> 2
    C -> 3
    ...
    Z -> 26
    AA -> 27 ...

题目描述：

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.

You may assume that the array is non-empty and the majority element always exist ...