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Leetcode - Minimum Cost

LC322, LC983, LC1105, LC1155, LC1130

Minimum Cost 很多求在各种情况下的最小消耗问题，大概是背包九讲的多重背包问题。 322. Coin Change 很简单的从所有可行状态中寻找最少的。O(N * M), O(1). class Solution { public int coinChange(int...

Posted by freeCookie🍪 on August 25, 2019

Leetcode - Math Related

LC813, LC837, LC1058

Math Related DP 数学不好orz。这类DP的状态转换不是很好找。 813. Largest Sum of Averages O(N * N * K), O(N * K). class Solution { public double largestSumOfAve...

Posted by freeCookie🍪 on August 25, 2019

Leetcode - Longest Subsequence

LC300, LC376, LC673, LC516, LC1027, LC873, LC368, LC842, LC960

Longest Subsequence 300. Longest Increasing Subsequence 这堆题开始的地方。。。寻找最长递增子序列。这题的思路是维护一个lis序列，如果可以递增的增加数字进去，就增加，如果不可以的话就把lis里的数字更新。通过每次与res进行比较就能得...

Posted by freeCookie🍪 on August 25, 2019

Leetcode - Longest Subarray and Substring

LC718, LC647

Longest Subarray and Substring Subarray & Substring是连续的，比起subsequence的状态转换要简单一些。经常是O(N * N), O(N)的解法。 718. Maximum Length of Repeated Subarra...

Posted by freeCookie🍪 on August 25, 2019

Leetcode - House Robber / Subarray Product

LC198, LC213, LC337, LC740, LC152, LC713

House Robber Leetcode DP tag下的一个抢劫系列问题。解决方法是1d动态规划。 House Robber 抢劫，不能连续抢两个挨着的房子，求最大收益。两个状态，抢，不抢。O(N), O(1). class Solution { public int ro...

Posted by freeCookie🍪 on August 25, 2019

Leetcode - Dominoes

LC833,

Dominoes 838. Push Dominoes 这题蛮好的，问推倒多米诺之后的结果。然后用two pointer做了。对于每一段多米诺。如果这一段左右状态相同，那么这一段都是这个状态。否则根据这一段的长度是否为奇数更新结果中的相应部分。O(N), O(1). class Solu...

Posted by freeCookie🍪 on August 25, 2019

Leetcode - Buy and Sell Stock

LC121, LC122, LC123, LC188, LC309, LC714

Best Time to Buy and Sell Stock Leetcode DP tag下的一个买股票系列问题。解决方法是1d动态规划，只要能够想清楚状态转换还是很好解决的。 Best Time to Buy and Sell Stock I - Easy 限定一次交易，求所得最大...

Posted by freeCookie🍪 on August 25, 2019

LC刷题自我检讨

自我检讨

刷题几个月的自我检讨 8月份了，开始投简历和约面试了。打开job description依旧还是这么的虚。看一眼面经也不能保证立刻有思路。刷题的时候有时候会觉得思路来的很快，有时候又觉得无论怎么样都不会有思路。痛定思痛，可能是我还是太懈怠了。只注意刷题没有关注业界需要的skills，抱残守缺...

Posted by freeCookie🍪 on August 24, 2019

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