[Leetcode] Longest Valid Parentheses @Python - Sumnous's Blog

[Leetcode] Longest Valid Parentheses @Python - Sumnous's Blog: " if s == '' or s == '(' or s == ')':
return 0
stack = [(-1, ')')]
maxLen = 0
for i in xrange(len(s)):
if s[i] == ')' and stack[-1][1] == '(':
stack.pop()
maxLen = max(maxLen, i - stack[-1][0])
else:
stack.append((i, s[i]))
return maxLen"



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霸气侧漏的在读博士

George E. Dahl: "George E. Dahl"





Currently, I am not on the job market. However, I expect to finish my Ph.D. this year. If you want to be notified when I start making post-graduation career plans and we haven't already spoken, please send me an email.



http://www.cs.toronto.edu/~gdahl/



[No offense, I just wish I can have the feeling of being a King like this guy]

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Programming Interview Questions

Programming Interview Questions:



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temp

http://www.cnblogs.com/zuoyuan/p/3700105.html
http://www.cnblogs.com/zzzdevil/p/3648348.html
http://www.cnblogs.com/zuoyuan/p/3703075.html

InstallingANewHardDrive - Community Help Wiki

InstallingANewHardDrive - Community Help Wiki:



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Clustering With K-Means in Python | The Data Science Lab

Clustering With K-Means in Python | The Data Science Lab:



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LeetCode题解整理版(二) | Coding 4 Fun

LeetCode题解整理版(二) | Coding 4 Fun: " i = len(s) - 1
while i >= 0 and s[i] == ' ': i -= 1
j = i - 1
while j >= 0 and s[j] != ' ': j -= 1
return 0 if i < 0 else i - j"



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[leetcode]Simplify Path @ Python - 南郭子綦 - 博客园

[leetcode]Simplify Path @ Python - 南郭子綦 - 博客园:



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[leetcode]Implement strStr() @ Python - 南郭子綦 - 博客园

[leetcode]Implement strStr() @ Python - 南郭子綦 - 博客园: " if len(haystack) < len(needle): return None
i = 0
while i < len(haystack)-len(needle)+1:
j = 0; k = i
while j < len(needle):
if haystack[k] == needle[j]:
j+=1; k+=1
else:
break
if j == len(needle):
break
else:
i+=1
if i == len(haystack)-len(needle)+1:
return None
else:
return haystack[i:]"



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[leetcode]Valid Palindrome @ Python - 南郭子綦 - 博客园

[leetcode]Valid Palindrome @ Python - 南郭子綦 - 博客园: " if s == '':
return True
else:
sTmp = ''
for i in range(0, len(s)):
if s[i] >= 'a' and s[i] <= 'z' or s[i] >= '0' and s[i] <= '9' or s[i] >= 'A' and s[i] <= 'Z':
sTmp += s[i]
sTmp = sTmp.lower()
for i in range(0, len(sTmp)/2):
if sTmp[i] != sTmp[len(sTmp)-1-i]:
return False
return True"



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[leetcode]Copy List with Random Pointer @ Python - 南郭子綦 - 博客园

[leetcode]Copy List with Random Pointer @ Python - 南郭子綦 - 博客园: "if head == None: return None
tmp = head
while tmp:
newNode = RandomListNode(tmp.label)
newNode.next = tmp.next
tmp.next = newNode
tmp = tmp.next.next
tmp = head
while tmp:
if tmp.random:
tmp.next.random = tmp.random.next
tmp = tmp.next.next
newhead = head.next
pold = head
pnew = newhead
while pnew.next:
pold.next = pnew.next
pold = pold.next
pnew.next = pold.next
pnew = pnew.next
pold.next = None
pnew.next = None
return newhead"



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[leetcode]Swap Nodes in Pairs @ Python - 南郭子綦 - 博客园

原题地址：http://oj.leetcode.com/problems/swap-nodes-in-pairs/

题意：将链表中的节点两两交换。Given 1->2->3->4, you should return the list as 2->1->4->3.

解题思路：这题主要涉及到链表的操作，没什么特别的技巧，注意不要出错就好。最好加一个头结点，操作起来会很方便。

代码：

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    # @param a ListNode
    # @return a ListNode
    def swapPairs(self, head):
        if head == None or head.next == None:
            return head
        dummy = ListNode(0); dummy.next = head
        p = dummy
        while p.next and p.next.next:
            tmp = p.next.next
            p.next.next = tmp.next
            tmp.next = p.next
            p.next = tmp
            p = p.next.next
        return dummy.next
        

[leetcode]Remove Nth Node From End of List @ Python - 南郭子綦 - 博客园

[leetcode]Remove Nth Node From End of List @ Python - 南郭子綦 - 博客园: " dummy=ListNode(0); dummy.next=head
p1=p2=dummy
for i in range(n): p1=p1.next
while p1.next:
p1=p1.next; p2=p2.next
p2.next=p2.next.next
return dummy.next"



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[leetcode]Add Two Numbers @ Python - 南郭子綦 - 博客园

[leetcode]Add Two Numbers @ Python - 南郭子綦 - 博客园:



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[leetcode]Rotate List @ Python - 南郭子綦 - 博客园

[leetcode]Rotate List @ Python - 南郭子綦 - 博客园: " if k == 0:
return head
if head == None:
return head
dummy = ListNode(0)
dummy.next = head
p = dummy
count = 0
while p.next:
p = p.next
count += 1
p.next = dummy.next
step = count - ( k % count )
for i in range(0, step):
p = p.next
head = p.next
p.next = None
return head"



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[leetcode]Plus One @ Python - 南郭子綦 - 博客园

[leetcode]Plus One @ Python - 南郭子綦 - 博客园: "class Solution:
# @param digits, a list of integer digits
# @return a list of integer digits
def plusOne(self, digits):
flag = 1
for i in range(len(digits)-1, -1, -1):
if digits[i] + flag == 10:
digits[i] = 0
flag = 1
else:
digits[i] = digits[i] + flag
flag = 0

if flag == 1:
digits.insert(0, 1)
return digits"



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[leetcode]Valid Sudoku @ Python - 南郭子綦 - 博客园

[leetcode]Valid Sudoku @ Python - 南郭子綦 - 博客园:



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How to Read Linux Top Command Output and Uses - TecAdmin.net

How to Read Linux Top Command Output and Uses - TecAdmin.net: "Using this article, I am trying to write to how to use and read results of top command."



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[leetcode]Valid Sudoku @ Python - 南郭子綦 - 博客园

[leetcode]Valid Sudoku @ Python - 南郭子綦 - 博客园:



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Dropped iphone 5 in water. Help? | Apple Support Communities

Dropped iphone 5 in water. Help? | Apple Support Communities: "I used the bag of rice method this weekend and it worked.  My iphone 5 had been in my pocket when I fell in our pool while cleaning the pool. So the phone was fully submerged for about 3-4 seconds. I could see water in the camera lens after this occured. It was definitely wet.
 
First I sucked the water out of the speaker holes with my mouth. Then I turned off the phone. Researched online and found the rice method. I put the phone in a ziplock bag with brown rice (it was all we had) about 45 minutes after the incident. A little while later I was able to find some silica gel packets in some vitamin bottles so I put those in the bag of rice with the phone (another technique found online).
 
The phone was in there from around 3:30 PM Saturday afternoon until 9:30 AM Monday morning. Took it out this morning and tried to turn it on but wouldn't - got the red low battery signal. After 10 minutes of charging it booted up on it's own. Works fine now. Hopefully it stays that way. By the way check your charger connector on the phone for rice. Luckily I looked before plugging it in. I tapped it on the desk and dislodged 3 pieces of rice that would have been smashed in there had I not checked first."



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[leetcode]Permutation Sequence @ Python - 南郭子綦 - 博客园

[leetcode]Permutation Sequence @ Python - 南郭子綦 - 博客园: " res = ''
k -= 1
fac = 1
for i in range(1, n): fac *= i
num = [1, 2, 3, 4, 5, 6, 7, 8, 9]
for i in reversed(range(n)):
curr = num[k/fac]
res += str(curr)
num.remove(curr)
if i !=0:
k %= fac
fac /= i
return res"



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C++11 improvements over C++03

Source:
http://www.cplusplus.com/articles/EzywvCM9/

About C++11

C++11 aka C++0x is the new standard of the C++ language, published in late 2011.
It supersedes the older C++03 standard, which was published in 2003.
Naturally, it brings improvements over the old standard, some of which this article will outline.

The revamped auto keyword

Verbosity is bad, mainly because it makes your code less clear.
So the auto keyword, a leftover from C, got a new meaning in C++11: automatic type deduction.

Example:

1 2 3 4 5 6

// the C++03 way for (std::vector<int>::const_iterator ci = v.begin(); ci != v.end(); ++ci); // the C++11 way for (auto ci = v.cbegin(); ci != v.cend(); ++ci); // notice the dedicated cbegin() and cend() member functions which return a const_iterator

Bad example:

1 2 3 4 5 6 7 8 9 10

auto x = 10.0; // if a newbie programmer changes `10.0' to `10', x becomes an integral type // and code depending on it to be a floating point type will fail // advice 1: use auto against verbosity, not consistency for (auto i = 0ul; i < v.size(); ++i); // this is just a clever way of writing `unsigned long int i=0' // advice 2: don't use auto if you specify the type, it defeats its purpose // advice 1+2=3: don't use auto with constants

Range-based for()

Iterating over the contents of STL containers is a very common operation.
C++11 now provides a specialized for() which can iterate over anything that has a begin() and an end() member function, which return the expected iterators.
It also works on plain C arrays.

Example:

1 2 3 4 5 6 7 8 9 10

// the C++03 way for (std::vector<int>::iterator i = v.begin(); i != v.end(); ++i); // the C++11 way for (int &item: v); // item will become, in order, all the things stored in v // notice how we're referencing the item, that allows us to change it for (const int &item: v); // can't change item, we reference it for speed for (int item: v); // can't change item, we're passing it by value

Initializer lists

The containers in C++03 could not be initialized as "naturally" as good old C-style arrays. That has changed.

Example:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

// C arrays char array1[] = {'A', 'B'}; double array2[] = {32.0, 6.003, -0.1}; // C++03 vectors std::vector<char> cpp03vector1; cpp03vector1.push_back('A'); cpp03vector1.push_back('B'); std::vector<double> cpp03vector2(3); cpp03vector2[0] = 32.0; cpp03vector2[1] = 6.003; cpp03vector2[2] = -0.1; // C++11 vectors std::vector<char> cpp11vector1 = {'A', 'B'}; std::vector<double> cpp11vector2 = {32.0, 6.003, -0.1}; // or... std::vector<char> cpp11vector3{'A', 'B'}; std::vector<double> cpp11vector4{32.0, 6.003, -0.1}; // notice that this works for all other containers as well, not just std::vector

Initializer lists can also be used for more complex structures.

Example:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

#include <map> #include <string> #include <vector> #include <utility> using namespace std; map<string, vector<pair<string, int>>> name_languages_year { {"Dennis Ritchie", {{"B", 1969}, {"C", 1973}}}, {"Niklaus Wirth", {{"Pascal", 1970}, {"Modula-2", 1973}, {"Oberon", 1986}}}, {"Bjarne Stroustrup", {{"C++", 1983}}}, {"Walter Bright", {{"D", 1999}}} }; // notice how the lists are nested to match the templates' parameters cout << name_languages_year["Niklaus Wirth"].at(0).first << endl; // prints `Pascal' // adds a new entry to the map name_languages_year["John McCarthy"] = { {"Lisp", 1958} }; // notice the lack of explicit types

C++ arrays

---

This is more of an addition than an improvement, but I decided to include it in the article anyway.

---

C++11 provides std::array, which has the purpose of replacing C arrays. It is a fixed-sized, lightweight alternative to the dynamically-sized std::vector.

Example:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

#include <array> // C arrays char carray1[] = "Abc"; // caution, an unseen '\0' is added to the end float carray2[] = {0.2f, 33.33f}; // C++ arrays std::array<char, 3> cpparray1{{'A', 'b', 'c'}}; std::array<float, 2> cpparray2{{0.2f, 33.33f}}; // observation 1: the size must be deducible at compile time // observation 2: the array cannot be resized // observation 3: the inner braces are due to the nature of initializer lists, // think of it as one list per template parameter // array test drive: the old versus the new std::cout << sizeof carray1 - 1; // -1 because of the extra '\0' std::cout << sizeof carray2 / sizeof (float); // because number of elements != number of bytes std::cout << cpparray1.size(); std::cout << cpparray2.size(); carray2[-5] = 0.1f; // do the moonwalk! cpparray2.at(-5) = 0.1f; // throws std::out_of_range exception // of course there are more reasons why C++ arrays are better than C arrays // but this example code section is already too big...

Minor fixes

C++03 had a bunch of minor glitches and design flaws which were fixed in C++11:

• Things like set<vector<int>> finally compile.
  Notice the lack of space between the last two angle brackets.


• std::string now has front() and back() member functions.


• File streams now accept an std::string as filename.
  This means one less use for the ridiculous c_str() member function.


• Easy conversion of numerical values to std::string is now possible through the use of the overloaded functions:
  string to_string(int)
string to_string(float)
string to_string(double)
...

Compiler support for C++11

... is not too bad. But give it a year or two to set.

The GNU C++ compiler requires the commandline parameter -std=c++0x to compile C++11 code.

Microsoft Visual Studio 2010 has partial support for C++11 features, out of the box.
Microsoft Visual Studio 201x (v11) will still only have partial support for C++11 features.

K-means算法及k-means++、SVD的优化 - 推酷

K-means算法及k-means++、SVD的优化 - 推酷:



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Programming Interview Questions

Programming Interview Questions:



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统计学习笔记（2）——感知机模型 - Liam Q的专栏 - 博客频道 - CSDN.NET

统计学习笔记（2）——感知机模型 - Liam Q的专栏 - 博客频道 - CSDN.NET:



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科学网—[转载]常见面试之机器学习算法思想简单梳理 - 李建扣的博文

科学网—[转载]常见面试之机器学习算法思想简单梳理 - 李建扣的博文:



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soulmachine/machine-learning-cheat-sheet

soulmachine/machine-learning-cheat-sheet:

https://github.com/soulmachine/machine-learning-cheat-sheet/raw/master/machine-learning-cheat-sheet.pdf



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美国一类优先移民EB1A

美国一类优先移民EB1A: "“EB-1A杰出人才”移民人数最少。获得“杰出人才”美国绿卡，大约只占当年百万新移民的千分之二"



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c++ - Compiling C++11 with g++

http://stackoverflow.com/questions/10363646/compiling-c11-with-g

Flags (or compiler options) are nothing but ordinary command line arguments passed to the compiler executable.

Assuming you are invoking g++ from the command line (terminal):

$ g++ -std=c++11 your_file.cpp -o your_program

or

$ g++ -std=c++0x your_file.cpp -o your_program

if the above doesn't work.