[LeetCode]Largest Number 解题报告 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/largest-number/#/description 题目描述: Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], t…

题目 Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of a…

在做 Largest Number 这道题之前,我对 sort 方法的用法是非常自信的.我很清楚不传比较因子的排序会根据元素字典序(字符串的UNICODE码位点)来排,如果要根据大小排序,需要传入一个比较函数. 先来看这道题,给你一个数组,让你把数组元素拼接起来,求能拼得的最大的数.如果只有两个数字 a 和 b,如何拼?很明显比较 ab 和 ba 两个数的大小,所以这道题首先需要对数组做一次排序.刷刷写下如下代码: nums.sort(function(a, b) { return (b + '…

# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com'https://oj.leetcode.com/problems/largest-number/ Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest…

Given a list of non negative integers, arrange them such that they form the largest number. Example 1: Input: [10,2] Output: "210" Example 2: Input: [3,30,34,5,9] Output: "9534330" Note: The result may be very large, so you need to ret…

Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of an i…

Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of an i…

Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of an i…

Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of an i…

Given a list of non negative integers, arrange them such that they form the largest number. Input: [10,2] Output: "210" Input: [3,30,34,5,9] Output: "9534330" 题意: 给定一堆数字,将它们排列顺序,使其连一块儿能形成最大的数. 思路: 先转化成一个字符串数组 然后把这个数组按特定规则排个序(熟练使用字符串的co…

这两个题几乎是一样的,只是leetcode的题是排成最大的数,剑指的题是排成最小的 179. Largest Number a.需要将数组的数转换成字符串,然后再根据大小排序,这里使用to_string函数将整数转换成字符串,比printf的方式简洁 b.cmp函数必须用static才能使用 c.这题需要排成最大的数,cmp函数如何确定< .>符合呢?cmp中可以默认为a就是两个字符中的第一个,b是第二个,所以a+b>b+a返回true就继续保持这样的排列.如果是<,a+b就会返回…

题目简述: Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead o…

Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of an i…

Given a list of non negative integers, arrange them such that they form the largest number.For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330.Note: The result may be very large, so you need to return a string instead of an int…

题目: Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n. For example: Given n = 13, Return 6, because digit 1 occurred in the following numbers: 1, 10, 11, 12, 13. 思路: 对这个数字的每一位求存在1的数字的…

Validate if a given string can be interpreted as a decimal number. Some examples:"0" => true" 0.1 " => true"abc" => false"1 a" => false"2e10" => true" -90e3   " => true" 1e…

We define the Perfect Number is a positive integer that is equal to the sum of all its positive divisors except itself. Now, given an integer n, write a function that returns true when it is a perfect number and false when it is not. Example: Input:…

题目链接:https://leetcode.com/problems/happy-number/ 题目理解:实现isHappy函数,判断一个正整数是否为happy数 happy数:计算要判断的数的每一位的平方和,平方和为1则为happy数,不为1则将原数替换为此平方和,继续上述步骤,直到等于1(为happy数),或者进入不包含1的无限循环(非happy数). 测试用例:19为happy数: 解题思路: 定义set集合存每次计算得到的需判断数n,循环计算新的原数n,终止条件为n等于1或者set中出…

In a given integer array nums, there is always exactly one largest element. Find whether the largest element in the array is at least twice as much as every other number in the array. If it is, return the index of the largest element, otherwise retur…

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…

In a given integer array nums, there is always exactly one largest element. Find whether the largest element in the array is at least twice as much as every other number in the array. If it is, return the index of the largest element, otherwise retur…

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…

class Solution { public: int singleNumber(int A[], int n) { ; ; ; i<=bits; i++) { ; ; ; j<n; j++) w += (A[j]>>(i-))&t; result+= (w%)<<(i-); //若是除过一个数之外,其他数重复k次,则将此处的3改为k } return result; } }; 利用二进制的位运算来解决这个问题,比如输入的数组是[2,2,3,2] 它们对应的二…

Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by…

class Solution { public: bool isPalindrome(int x) { ,init=x; ) return true; ) return false; ){ r=r*+init%; init=init/; } if(r==x) return true; else return false; } }; 题目: 判断一个整数是不是回文数,即一个数翻转过来是否跟原来的数仍一样. 需要考虑负数,负数无回文数. 解法: 翻转提供的数字,即123的话,需要翻转为321. 再判…

此题主要是讲给你一组数,如何将数连在一起能得到最大值(最小值反之),注意局部最优,就是说如果 123 234两个连在一起怎么样最大,显然是234123比123234大,对于3个数我们可以找到类似的性质,4个数一样...因此我们得到这个局部最优的排序是全局最优的.因此这个实现最核心的代码就是函数cmp,其他的就是要注意全是0的情况和前导0的情况,这题就轻松解决. inline bool cmp(const std::string &a, const std::string &b) { ret…

class Solution { public: int singleNumber(int A[], int n) { int i,j; ; i<n; i++) { ; j<n; j++) { if(A[j]==A[i]) { ]; A[i+] = A[j]; A[j] = temp; i++; break; } } if(j==n) return A[i]; } } }; 上面的是传统方法,时间复杂度是O(n2),空间复杂度是O(1). class Solution { public: in…

题目: Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array. Example 1: Input: [3,0,1] Output: 2 Example 2: Input: [9,6,4,2,3,5,7,0,1] Output: 8 Note:Your algorithm should run in linear run…

题目链接 题目要求: Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string inst…

Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of an i…