Yuliang-Lee
4/15/2018 - 8:34 AM

leetCode impressive solutions

collect leetCode's impressive solutions of algorithm problems

  1. Shortest Unsorted Continuous Subarray

Given an integer array, you need to find one continuous subarray that if you only sort this subarray in ascending order, then the whole array will be sorted in ascending order, too.

You need to find the shortest such subarray and output its length.

Example 1:

Input: [2, 6, 4, 8, 10, 9, 15]
Output: 5
Explanation: You need to sort [6, 4, 8, 10, 9] in ascending order to make the whole array sorted in ascending order.

Note:

  • Then length of the input array is in range [1, 10,000].
  • The input array may contain duplicates, so ascending order here means <=.

solution

https://leetcode.com/problems/shortest-unsorted-continuous-subarray/discuss/103057/Java-O(n)-Time-O(1)-Space/106310

  1. intersection-of-two-linked-lists

Write a program to find the node at which the intersection of two singly linked lists begins.

For example, the following two linked lists:

A:          a1 → a2
                   ↘
                     c1 → c2 → c3
                   ↗            
B:     b1 → b2 → b3

begin to intersect at node c1.

Notes:

  • If the two linked lists have no intersection at all, return null.
  • The linked lists must retain their original structure after the function returns.
  • You may assume there are no cycles anywhere in the entire linked structure.
  • Your code should preferably run in O(n) time and use only O(1) memory.

solution

Java solution without knowing the difference in len!