There is a ball in a maze with empty spaces and walls. The ball can go through empty spaces by rolling up, down, left or right, but it won't stop rolling until hitting a wall. When the ball stops, it could choose the next direction. Given the ball's 

原题地址:https://oj.leetcode.com/problems/permutations-ii/ 题意: Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example,[1,1,2] have the following unique permutations:[1,1,2], [1,2,1], and [2,1,1].

原题地址:https://oj.leetcode.com/problems/subsets-ii/ 题意: Given a collection of integers that might contain duplicates, S, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicat

原题地址:https://oj.leetcode.com/problems/n-queens-ii/ 题意:和N-Queens这道题其实是一样的,只不过这次要求返回的时N皇后的解的个数的问题. 解题思路:上道题使用了递归回溯的解法,这道题我们可以使用非递归回溯来解决,因为如果使用递归回溯来解决,那么代码和上道题几乎一样.在非递归的编程中,比较有技巧性的是如何来进行回溯. 代码: class Solution: # @return an integer def totalNQueens(self,

[leetcode]Word Ladder II @ Python 原题地址:http://oj.leetcode.com/problems/word-ladder-ii/ 参考文献:http://blog.csdn.net/doc_sgl/article/details/13341405   http://chaoren.is-programmer.com/ 题意:给定start单词,end单词,以及一个dict字典.要求找出start到end的所有最短路径,路径上的每个单词都要出现在dict

作者:jostree  转载请注明出处 http://www.cnblogs.com/jostree/p/4051169.html 题目链接:leetcode Permutations II 无重全排列 题目要求对有重复的数组进行无重全排列.为了保证不重复,类似于全排列算法使用dfs,将第一个数字与后面第一次出现的数字交换即可.例如对于序列1,1,2,2 有如下过程: ,1,2,2 -> 1,,2,2 -> 1,1,,2 -> 1,1,2,  -> 1,2,,2 -> 1,2

(╭￣3￣)╭ 小希的迷宫II TimeLimit: 2000/1000 MS (Java/Others)  MenoryLimit: 65536/32768 K (Java/Others) 64-bit integer IO format:%I64d   Problem Description 上次Gardon的迷宫城堡小希玩了很久,现在她也想设计一个迷宫让Gardon来走.但是她设计迷宫的思路不一样,首先她认为所有的通道都应该是单向连通的,就是说如果有一个通道连通了房间A和B,那么它只能从房

转自:http://blog.csdn.net/holymaple/article/details/8636234 由于迷宫的设计,老鼠走迷宫的入口至出口路径可能不止一条,如何求出所有的路径呢? 解法:求所有的路径困哪起来复杂但其实更简单,只要在老鼠走到出口时显示经过的路径,然后退回上一格重新选择下一个位置继续递回就可以了,比求出单一路径更简单,程序只需要做一点点修改就行了. C++版: 1 /* 2 *内容:老鼠走迷宫II 3 *时间:3/01/2013 4 */ 5 6 #include <

题目来源 https://leetcode.com/problems/pascals-triangle-ii/ Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3,Return [1,3,3,1]. 题意分析 Input:integer Output:kth row of the Pascal's triangle Conditions:只返回第n行 题目思路 同118,不

题目来源 https://leetcode.com/problems/path-sum-ii/ Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. 题意分析 Input: a binary tree, sum Output: list of list. Conditions: 给定一个二叉树,将所有root-leaf的路径值和等于sum的路径返

题目来源 https://leetcode.com/problems/binary-tree-level-order-traversal-ii/ Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root). 题意分析 Input: binary tree Output:

题目来源 https://leetcode.com/problems/reverse-linked-list-ii/ Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. Note:G

题目来源 https://leetcode.com/problems/subsets-ii/ Given a collection of integers that might contain duplicates, nums, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate su

题目来源 https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/ Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list. For example,Given 1->2->3->3->4->4->

题目来源 https://leetcode.com/problems/search-in-rotated-sorted-array-ii/ Follow up for "Search in Rotated Sorted Array":What if duplicates are allowed? Would this affect the run-time complexity? How and why? Write a function to determine if a given

题目来源 https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/ Follow up for "Remove Duplicates":What if duplicates are allowed at most twice? For example,Given sorted array nums = [1,1,1,2,2,3], Your function should return length = 

题目来源 https://leetcode.com/problems/unique-paths-ii/ Follow up for "Unique Paths": Now consider if some obstacles are added to the grids. How many unique paths would there be? An obstacle and empty space is marked as 1 and 0 respectively in the g

题目来源 https://leetcode.com/problems/permutations-ii/ Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example,[1,1,2] have the following unique permutations:[1,1,2], [1,2,1], and [2,1,1]. 题意分析In

题目来源 https://leetcode.com/problems/jump-game-ii/ Given an array of non-negative integers, you are initially positioned at the first index of the array. Each element in the array represents your maximum jump length at that position. Your goal is to re

题目来源 https://leetcode.com/problems/spiral-matrix-ii/ Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. 题意分析 Input: n:integer Output:a matrix decribed as list[list[]] Conditions:输入一个大小,得到一个方形矩阵,然后形成蛇形矩阵 题目