Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. Each number in C may only be used once in the combination. Note: All numbers (including target) will be posi…

Write a program to solve a Sudoku puzzle by filling the empty cells. Empty cells are indicated by the character '.'. You may assume that there will be only one unique solution. A sudoku puzzle... ...and its solution numbers marked in red. 题意分析: 本题是要解…

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order. You may assume no duplicates in the array. Here are few examples.[1,3,5,6], 5 → 2[1,3,5,6], 2 →…

算法和数据结构知识点图 首先,了解算法和数据结构有哪些知识点,在后面的学习中有 大局观,对学习和刷题十分有帮助. 下面是我花了一天时间花的算法和数据结构的知识结构,大家可以看看. 后面是为大家 精心挑选的LeetCode题单,并根据题目知识点的类型分好了类别,大家可以根据每个知识点,进行有针对性的刷题. 数据结构 数组&双指针 LeetCode 1. 两数之和 LeetCode 4. 寻找两个正序数组的中位数 LeetCode 15. 三数之和 LeetCode 75. 颜色分类 LeetCod…

1. Rotate List Given a list, rotate the list to the right by k places, where k is non-negative. Example: Given 1->2->3->4->5->NULL and k = 2, return 4->5->1->2->3->NULL. 思路:这题感觉有点没有说清楚,如果k大于了链表长度该怎么办呢?这个时候怎么确定旋转位置呢?从右往左数,超出数组…

Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in-place. Example 1: Input: [   [1,1,1],   [1,0,1],   [1,1,1] ] Output: [   [1,0,1],   [0,0,0],   [1,0,1] ] Example 2: Input: [   [0,1,2,0],   [3,4,5,2],   [1,3,1,5]…

Given a positive integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. Example: Input: 3 Output: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ]思路 之前做过一个旋转数组的题,当时是旋转打印矩阵,这次只是构造一个旋转数组.方案还是一样的,条件变量也一样.时间复杂度为O(n*n), 空间复杂度为O(n)…

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. Example 1: Input: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] Output: [1,2,3,6,9,8,7,4,5] Example 2: Input: [ [1, 2, 3, 4], [5, 6, 7, 8], [9,10,11,…

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. For example,Given n = 3, You should return the following matrix: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ] 题解:以前做过的Spiral Matrix是给一个矩阵螺旋式的输出,这道题是给一个n,螺旋式的…

Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place. 题解:因为题目要求原地算法,所以我们只能利用矩阵第一行和第一列存放置零信息. 首先遍历第一行和第一列,看他们是否需要全部置零,用两个变量first_column_zero和first_row_zero来记录: 遍历矩阵,如果某个位置matrix[i][j]出现了0,就把matrix[i][0]和Matrix[0…