【京东2018秋招PHP开发工程师笔试题】疯狂序列

【牛客】2018京东秋招数据分析工程师笔试解析 【牛客】2018京东秋招数据分析工程师笔试解析 * 根据牛客网下方讨论整理(https://www.nowcoder.com/test/10630596/summary) 一、选择 1、有一个文件user.txt,每行一条user记录,共若干行,下面哪个命令可以实现“统计出现次数最多的前3个user及其次数”? 答:sort user.txt | uniq -c | sort -rn | ... 阅读详情

题目描述:

东东从京京那里了解到有一个无限长的数字序列: 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, …(数字k在该序列中正好出现k次)。东东想知道这个数字序列的第n项是多少,你能帮帮他么


输入描述:

输入包括一个整数n(1 ≤ n ≤ 10^18)


输出描述:

输出一个整数,即数字序列的第n项

示例1
输入
169
输出
18

参考程序:

#include<iostream>
#include<math.h>
#include<iomanip>
using namespace std;
int main(){
    long long k = 0;
 
京东2018秋招PHP笔试题解析:从基础到安全实战 PHP开发者在面试中常被考察的不仅是语法熟练度,更是从字符串处理、数组排序到面向对象设计的综合工程能力。理解substr与mb_substr的字节差异、掌握array_multisort的多维排序逻辑,是应对笔试的基础。同时,网络协议中的跨域与JSONP方案、PHP伪协议与文件包含的防御策略,以及反序列化安全漏洞的防护,都是区分普通开发者与高级工程师的关键考点。数据库层面,PDO预处理为何能有效防止SQL注入,索引设计与事务隔离级别如何优化生产性能,同样值得深入掌握。以京东2018秋招PHP笔试题为线索,系 阅读详情

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% Dropout fraction opts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex4 neural net with sigmoid activation functionrand('state',0)nn = nnsetup([784 100 10]);nn.activation_function = 'sigm'; % Sigmoid activation functionnn.learningRate = 1; % Sigm require a lower learning rateopts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex5 plotting functionalityrand('state',0)nn = nnsetup([784 20 10]);opts.numepochs = 5; % Number of full sweeps through datann.output = 'softmax'; % use softmax outputopts.batchsize = 1000; % Take a mean gradient step over this many samplesopts.plot = 1; % enable plottingnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex6 neural net with sigmoid activation and plotting of validation and training error% split training data into training and validation datavx = train_x(1:10000,:);tx = train_x(10001:end,:);vy = train_y(1:10000,:);ty = train_y(10001:end,:);rand('state',0)nn = nnsetup([784 20 10]); 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