Given a collection of integers that might contain duplicates, nums, return all possible subsets (the power set).
Note: The solution set must not contain duplicate subsets.
Example:
Input: [1,2,2] Output: [ [2], [1], [1,2,2], [2,2], [1,2], [] ]
Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.
Note:
The number of elements initialized in nums1 and nums2 are m and n respectively.
You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2.
Example:
Input: nums1 = [1,2,3,0,0,0], m = 3 nums2 = [2,5,6], n = 3 Output: [1,2,2,3,5,6]
将nums1、nums2两个有序数组合并到nums1一个中，nums1已分配足够空间存放元素。
Given a 2D binary matrix filled with 0’s and 1’s, find the largest rectangle containing only 1’s and return its area.
Example:
Input:
[
["1","0","1","0","0"],
["1","0","1","1","1"],
["1","1","1","1","1"],
["1","0","0","1","0"]
]
Output: 6
在给出的矩阵中，1表示元素，0表示空，找出最大矩形的面积。
Largest Rectangle in Histogram
Given n non-negative integers representing the histogram’s bar height where the width of each bar is 1, find the area of largest rectangle in the histogram.
Above is a histogram where width of each bar is
1, given height =[2,1,5,6,2,3].
The largest rectangle is shown in the shaded area, which has area =
10unit.
给出一个直方图，求最大矩形面积。
Search in Rotated Sorted Array II
Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
(i.e.,
[0,0,1,2,2,5,6]might become[2,5,6,0,0,1,2]).You are given a target value to search. If found in the array return
true, otherwise returnfalse.Example 1:
Input: nums = [2,5,6,0,0,1,2], target = 0 Output: trueExample 2:
Input: nums = [2,5,6,0,0,1,2], target = 3 Output: falseFollow up:
- This is a follow up problem to Search in Rotated Sorted Array, where nums may contain duplicates.
- Would this affect the run-time complexity? How and why?
Remove Duplicates from Sorted Array II
Given a sorted array nums, remove the duplicates in-place such that duplicates appeared at most twice and return the new length.
Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
Example 1:
Given nums = [1,1,1,2,2,3], Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3 respectively. It doesn't matter what you leave beyond the returned length.Example 2:
Given nums = [0,0,1,1,1,1,2,3,3], Your function should return length = 7, with the first seven elements of nums being modified to 0, 0, 1, 1, 2, 3 and 3 respectively. It doesn't matter what values are set beyond the returned length.
在有序数组中删除重复的元素，每个元素允许重复一次（出现两次）。
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 cell, where “adjacent” cells are those horizontally or vertically neighboring. The same letter cell may not be used more than once.
Example:
board =
[
['A','B','C','E'],
['S','F','C','S'],
['A','D','E','E']
]
Given word = "ABCCED", return true.
Given word = "SEE", return true.
Given word = "ABCB", return false.
在board中查找是否存在相连（相邻）的字符与给定的单词对应。
很像一个走迷宫的题目，搜索下一步是否与单词的字母匹配，是则走到该位置。
