Dynamic Programming 实际上是[LeetCode] 系统刷题4_Binary Tree & Divide and Conquer的基础上,加上记忆化的过程.就是说,如果这个题目实际上是类似于Divide and conquer或者说是DFS,但是在计算过程中有很多重复计算同样的过程的话,那么就可以用Dynamic prgramming/记忆化搜索来完成.基本就是利用空间来简化时间复杂度的过程. 可以/很有可能使用Dynamic programming的条件,满足之一即可. 1.
118. Pascal's Triangle Easy 87984FavoriteShare Given a non-negative integer numRows, generate the first numRows of Pascal's triangle. In Pascal's triangle, each number is the sum of the two numbers directly above it. Example: Input: 5 Output: [ [1],
习惯就是人生的最大指导 ——休谟 24. Swap Nodes in Pairs Medium 1209107FavoriteShare Given a linked list, swap every two adjacent nodes and return its head. You may not modify the values in the list's nodes, only nodes itself may be changed. 防止用增加值,存储前后变量只进行值交换,而不处理
1.两数之和 解法1 两次for或者for+indexOf var twoSum = function (nums, target) { let len = nums.length for (let i = 0; i < len; i++) { let j = nums.indexOf(target - nums[i], i + 1) if (j !== -1) { return [i, j] } } }; 解法2 var twoSum = function (nums, target) { l
7 Reverse Integer Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Note:Assume we are dealing with an environment which could only stor