LeetCode 个人分类
2018-05-17
数组 11. Container With Most Water 15. 3Sum 16. 3Sum Closest 26. Remove Duplicates from Sorted Array 27. Remove Element 31. Next Permutation 42. Trapping Rain Water 48. Rotate Image 54. Spiral Matrix 59. Spiral Matrix II 60. Permutation Sequence 73. Set Matrix Zeroes 75. Sort Colors 80. Remove Duplicates from Sorted Array II 88. Merge Sorted Array 118. Pascal’s Triangle 119. Pascal’s Triangle II 链表 2. Add…
Best Time to Buy and Sell Stock III
2018-05-04
股票买入卖出的最佳时间问题: https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii/ Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete at most two transactions. Note: You may not engage in multiple transactions at the same time (i.e., you must sell the stock before you…
牛顿法实现开平方 sqrt
2018-04-30
在精度要求较低的情况下,可以用二分查找实现开平方,例如 Sqrt(x) - LeetCode 就只需返回 int,即精确到个位。 在求更高精度开平方时,可以利用牛顿法。 从泰勒公式…
批量构建二叉查找树时的一个常见错误
2018-04-03
给定一个正整数 n,生成结点值为 1 ~ n 的所有二叉查找树: https://leetcode.com/problems/unique-binary-search-trees-ii/ Given an integer n, generate all structurally unique BST’s (binary search trees) that store values 1…n. For example, Given n = 3, your program should return all 5 unique BST’s shown below. 1 3 3 2 1 \ / / / \…
二叉树非递归遍历算法的快速实现
2018-03-25
二叉树的递归遍历简洁明了,而非递归遍历则相对复杂,三种递归思路有很大区别,还容易忘。如果不用线索二叉树的话,一般要用栈来实现,即便都是用栈实…
Floyd 判圈算法
2017-12-01
判断一个单链表中是否存在环,并找出环的入口: https://leetcode.com/problems/linked-list-cycle-ii/ Given a linked list, return the node where the cycle begins. If there is no cycle, return null. Note: Do not modify the linked list. Follow up: Can you solve it without using extra space? 不知道 LeetCode 难度评级的标准是…
Single Number II
2017-11-27
LeetCode 的一道题,在一个 int 数组中,其余数值均出现了 3 次,只有一个数值出现了 1 次,求这个数: https://leetcode.com/problems/single-number-ii/description/ Given an array of integers, every element appears three times except for one, which appears exactly once. Find that single one. Note: Your algorithm should have a…
Gas Station
2017-10-14
加油站问题,LeetCode 链接: https://leetcode.com/problems/gas-station/description/ There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an empty tank…