01 2015 档案

[leetcode] Word Search
摘要：题目：（Backtrancing）Given a 2D board and a word, find if the word exists in the grid.The word can be constructed from letters of sequentially adjacent ce... 阅读全文
posted @ 2015-01-08 22:48 fengmang 阅读(174) 评论(0) 推荐(0)
[leetcode] Construct Binary Tree from Preorder and Inorder Traversal
摘要：题目：Given preorder and inorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree./** * Defini... 阅读全文
posted @ 2015-01-06 03:00 fengmang 阅读(121) 评论(0) 推荐(0)
[leetcode] Flatten Binary Tree to Linked List
摘要：题目（Tree DFS）Given a binary tree, flatten it to a linked list in-place.For example,Given 1 / \ 2 5 / \ \ 3 4 6The... 阅读全文
posted @ 2015-01-06 02:37 fengmang 阅读(147) 评论(0) 推荐(0)
[leetcode] Recover Binary Search Tree
摘要：题目：（Tree ，DFS）Two elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Note:A solution using ... 阅读全文
posted @ 2015-01-06 01:39 fengmang 阅读(130) 评论(0) 推荐(0)
[leetcode] Unique Binary Search Trees II
摘要：题目：（DP）Givenn, generate all structurally uniqueBST's(binary search trees) that store values 1...n.For example,Givenn= 3, your program should return al... 阅读全文
posted @ 2015-01-06 00:09 fengmang 阅读(190) 评论(0) 推荐(0)
[leetcode summary] Dynamic Programming
摘要：套路：一般有两个string的时候 都建二维的数组来存。int[][] dp =new int[len+1][len+1];初始情况已设立dp[0][0] = 1;递归循环for()dp[i][j] = dp [i-1][j];交答案dp[len][len] 阅读全文
posted @ 2015-01-05 22:16 fengmang 阅读(134) 评论(0) 推荐(0)
[leetcode] Generate Parentheses
摘要：题目：（Backtrancing）Givennpairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, givenn= 3, a soluti... 阅读全文
posted @ 2015-01-03 03:28 fengmang 阅读(77) 评论(0) 推荐(0)
[leetcode summary] Backtracing
摘要：主线是reshelper（res）；dfs（）；helper（res，num，curr, index, resultOne, visited..）{ if(curr==num) 1 res.add(resultOne); 2 res.add(new resultOne); e... 阅读全文
posted @ 2015-01-03 01:19 fengmang 阅读(148) 评论(0) 推荐(0)
[leetcode] Distinct Subsequences
摘要：题目：(DP)Given a stringSand a stringT, count the number of distinct subsequences ofTinS.A subsequence of a string is a new string which is formed from t... 阅读全文
posted @ 2015-01-02 10:13 fengmang 阅读(154) 评论(0) 推荐(0)
[leetcode] Scramble string
摘要：题目：Given a strings1, we may represent it as a binary tree by partitioning it to two non-empty substrings recursively.Below is one possible representat... 阅读全文
posted @ 2015-01-02 04:06 fengmang 阅读(123) 评论(0) 推荐(0)
[leetcode] Unique Binary Search Trees
摘要：题目：（DP）Givenn, how many structurally uniqueBST's(binary search trees) that store values 1...n?For example,Givenn= 3, there are a total of 5 unique BST... 阅读全文
posted @ 2015-01-02 03:43 fengmang 阅读(183) 评论(0) 推荐(0)
[leetcode] Word Break2
摘要：题目：(DP, Backtracing)Given a stringsand a dictionary of wordsdict, add spaces insto construct a sentence where each word is a valid dictionary word.Ret... 阅读全文
posted @ 2015-01-02 01:53 fengmang 阅读(261) 评论(0) 推荐(0)
[leetcode Summary] BFS
摘要：BFS有固定的套路 类似下面这个形式ArrayList queue = new ArrayList();queue.add(root);while(!queue.isEmpty()){ String temp = queue.poll(); for(neigbor : t... 阅读全文
posted @ 2015-01-01 11:07 fengmang 阅读(100) 评论(0) 推荐(0)
[leetcode] Word Ladder2
摘要：题目：Given two words (startandend), and a dictionary, find all shortest transformation sequence(s) fromstarttoend, such that:Only one letter can be chan... 阅读全文
posted @ 2015-01-01 10:44 fengmang 阅读(187) 评论(0) 推荐(0)
[leetCode Summary] LinkedList
摘要：几个套路第一 fast slow 找中点，找位数。第二 reverse{ ListNode last = prev.next; ListNode curr = last.next; while(curr!=null) { last.next = curr.next; ... 阅读全文
posted @ 2015-01-01 07:02 fengmang 阅读(111) 评论(0) 推荐(0)
[leetcode] Binary Tree Postorder Traversal
摘要：题目：（Tree ，Stack）Given a binary tree, return thepostordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3... 阅读全文
posted @ 2015-01-01 06:51 fengmang 阅读(105) 评论(0) 推荐(0)
[leetcode] Largest Rectangle in Histogram
摘要：题目：（Stack）Givennnon-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in ... 阅读全文
posted @ 2015-01-01 04:39 fengmang 阅读(144) 评论(0) 推荐(0)
[leetcode] Reverse Linked List II
摘要：题目：（LinkedList）Reverse a linked list from positionmton. Do it in-place and in one-pass.For example:Given1->2->3->4->5->NULL,m= 2 andn= 4,return1->4->3... 阅读全文
posted @ 2015-01-01 01:01 fengmang 阅读(85) 评论(0) 推荐(0)