riskys的博客

题目链接：https://leetcode.com/problems/power-of-three/ Given an integer, write a function to determine if it is a power of three. 有两种解法：非递归和递归，分别如下： class Solution { public: bool isPowerOfThree(i

问题链接：点击打开链接 Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2). The above rectangle

问题链接：https://leetcode.com/problems/count-of-smaller-numbers-after-self/?tab=Description You are given an integer array nums and you have to return a new counts array. The counts array has the pro

问题链接：点击打开链接 Given an unsorted array of integers, find the length of longest increasing subsequence. For example, Given [10, 9, 2, 5, 3, 7, 101, 18], The longest increasing subsequence is [2,

问题链接：点击打开链接 原文链接：http://blog.youkuaiyun.com/sbitswc/article/details/50191729 Additive number is a string whose digits can form additive sequence. A valid additive sequence should contain at least t

问题链接：点击打开链接 According to the Wikipedia's article: "The Game of Life, also known simply as Life, is a cellular automaton devised by the British mathematician John Horton Conway in 1970." Give

问题链接：点击打开链接 Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume that there is only one dup

Implement the following operations of a stack using queues. push(x) -- Push element x onto stack.pop() -- Removes the element on top of the stack.top() -- Get the top element.empty() -- Return whet

问题链接：https://leetcode.com/problems/ugly-number/?tab=Description Write a program to check whether a given number is an ugly number. Ugly numbers are positive numbers whose prime factors only in

问题链接：点击打开链接 Given an array of integers, find out whether there are two distinct indices i and j in the array such that the absolute difference betweennums[i] and nums[j] is at most t and the ab

问题链接：https://leetcode.com/problems/ugly-number-ii/?tab=Description Write a program to find the n-th ugly number. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For

问题链接：https://leetcode.com/problems/super-ugly-number/?tab=Description Write a program to find the nth super ugly number. Super ugly numbers are positive numbers whose all prime factors are in

原文链接：https://leetcode.com/problems/max-points-on-a-line/?tab=Description Given n points on a 2D plane, find the maximum number of points that lie on the same straight line. 要求：求出平面n个点中，最多共线的点数。

问题链接：点击打开链接 Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. The update(i, val) function modifies nums by updating the element at index i

问题链接：点击打开链接 题目： You are given two jugs with capacities x and y litres. There is an infinite amount of water supply available. You need to determine whether it is possible to measure exactl

问题链接：点击打开链接 One way to serialize a binary tree is to use pre-order traversal. When we encounter a non-null node, we record the node's value. If it is a null node, we record using a sentinel value

Find the largest rectangular area possible in a given histogram where the largest rectangle can be made of a number of contiguous bars. For simplicity, assume that all bars have same width and the wid

问题链接：点击打开链接 Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. Example: Given nums = [-2, 0, 3, -5, 2, -1] sumRange(0, 2) -> 1 sumRange(2

问题链接：点击打开链接 You are playing the following Bulls and Cows game with your friend: You write down a number and ask your friend to guess what the number is. Each time your friend makes a guess, you

题目链接：https://leetcode.com/problems/maximum-product-of-word-lengths/ Given a string array words, find the maximum value of length(word[i]) * length(word[j]) where the two words do not share

原文链接：http://blog.youkuaiyun.com/baidu_23318869/article/details/50891006 问题链接：https://leetcode.com/problems/coin-change/ 代码如下： [cpp] view plain copy   // CPP   class Sol

问题链接：https://leetcode.com/problems/valid-perfect-square/ 原文：http://www.cnblogs.com/guoguolan/p/5619443.html Given a positive integer num, write a function which returns True if num is a perfect

原文链接：http://blog.youkuaiyun.com/baidu_23318869/article/details/50386323 问题链接：https://leetcode.com/problems/bulb-switcher/ [cpp] view plain copy // CPP   class Solutio

题目链接：https://leetcode.com/problems/count-numbers-with-unique-digits/ Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x n. Example: Given n = 2, return 91.

问题链接：点击打开链接 Given an unsorted array return whether an increasing subsequence of length 3 exists or not in the array. Formally the function should: Return true if there exists i, j, k  su

题目链接：https://leetcode.com/problems/wiggle-sort-ii/ 我的解题思路：先用快排从小到大排序，然后分别将前半段数据和后半段数据依次插入，若有中间数据，则放在最后即是题目要求的格式。 public class Solution {     public void wiggleSort(int[] nums) {         if(num

问题链接：https://leetcode.com/problems/intersection-of-two-arrays/ Given two arrays, write a function to compute their intersection. Example: Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return

问题链接：https://leetcode.com/problems/intersection-of-two-arrays-ii/ Given two arrays, write a function to compute their intersection. Example: Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], retu

问题链接：https://leetcode.com/problems/missing-number/ Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array. For example, Given n

问题链接：https://leetcode.com/problems/integer-to-english-words/?tab=Description Convert a non-negative integer to its english words representation. Given input is guaranteed to be less than 231 - 1.

问题链接：https://leetcode.com/problems/first-bad-version/?tab=Description You are a product manager and currently leading a team to develop a new product. Unfortunately, the latest version of your pr

问题链接：https://leetcode.com/problems/perfect-squares/ Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n. For example, g

问题链接：https://leetcode.com/problems/move-zeroes/?tab=Description Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero e

问题链接：https://leetcode.com/problems/word-pattern/?tab=Description Given a pattern and a string str, find if str follows the same pattern. Here follow means a full match, such that there is a

问题链接：https://leetcode.com/problems/nim-game/ 转载来源：http://blog.youkuaiyun.com/fly_yr/article/details/50071367 You are playing the following Nim Game with your friend: There is a heap of stones on the t

题意：有n个相当于水桶的隔板，求使用两个隔板和底部x轴所能组成的水桶可以装载的最大容量。 第一种方法：两层遍历，第一层从0遍历到n-2，第二层从i+1遍历到n-1，每次求得（j-i）*（Math.min(height【i】，height【j】)）与max比较，使max总是保存最大值。 缺点：需要n*n时间 第二种方法：线性时间，两个指针分别从0、n-1开始向中间靠拢，直到左指针不小于