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…

Given an array of integers, every element appears three times except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 题解:线性时间,O(1)的空间复杂度,只能把整数写成二进制的形式运算了.具体…

题目: Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 看了别人的解答才会的,利用公式a XOR b XOR a = b,从A[n]开始…

[Q7]  把数倒过来 Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Solution: https://leetcode.com/problems/reverse-integer/discuss/229800/Pyt…

The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1. That is, F(0) = 0,   F(1) = 1 F(N) = F(N - 1) + F(N - 2), for N > 1. Given…

Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight). For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011, so the function should retu…

Related to question Excel Sheet Column Title Given a column title as appear in an Excel sheet, return its corresponding column number. For example: A -> 1 B -> 2 C -> 3 ... Z -> 26 AA -> 27 AB -> 28 题解:其实就是一个26进制数转换成十进制数的程序:s[0]*26^(n-1)…