https://www.lintcode.com/problem/1850 Since Alice and Bob are working on separate consecutive apple trees without overlap, I thought of using sliding window to solve this problem. We can iterate all the possible dividers in the array, and each iteration, we find the… Read More »Lintcode 1850 Pick Apples
https://leetcode.com/problems/grumpy-bookstore-owner/description When I see the minutes is consecutive, I thought of sliding window immediately. We will iterate all the possible window with the fixed length and see which one produces the max result. Let’s take a look at the solution… Read More »Leetcode 1052 Grumpy Bookstore Owner
https://www.lintcode.com/problem/183 The obvious intuition is to try every possible length to cut the wood and see if they meet the requirement, during which we find the max value. So this is similar to search through a number within a range… Read More »Lintcode 183 Wood Cut
https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/description Obviously this problem can be solved by looping through the array once and find the first element that’s smaller then the previous one. Easy! But we are actually asked to solve it in O(log n) time. As soon as… Read More »Leetcode 153 Find Minimum in Rotated Sorted Array
https://leetcode.com/problems/heaters/description This is a very interesting problem because it has a couple of train of thoughts for the solution. First let’s take a look at the assumptions, looks like the heaters and houses are not guaranteed to be sorted arrays.… Read More »Leetcode 475 Heaters
https://www.lintcode.com/problem/1375 Example 1: Example 2: This problem can also use the two pointers method we talked about in https://leetcode-solution.com/leetcode-209-minimum-size-subarray-sum-2/ with time complexity of O(n) The idea is the same, iterate the left pointer, at each iteration, find the right pointer… Read More »Lintcode 1375 Substring With At Least K Distinct Characters
https://leetcode.com/problems/minimum-size-subarray-sum/description This is quite an interesting problem since it has a couple of interesting solutions that can be extend to other problems and how you think about algorithms in general. The most naive way of thinking is to just brute… Read More »Leetcode 209 Minimum Size Subarray Sum
Description Given an array of integers and an integer k, you need to find the minimum size of continuous no-empty subarrays whose sum equals to k, and return its length. if there are no such subarray, return -1. the integer nums[i] may… Read More »Lintcode 1844 subarray sum equals to k II
We will use stacks to solve this problem. A couple tricky thing to note: Solution
For Javascript users, we can utilized an array to implement most of the functionalities in O(1) time since both push and pop from array are constant time operations. But for getMin we need to keep another stack called minStack to… Read More »Leetcode 155 Min Stack