the-method-of-programming-1

1.1的举一反三

单词翻转

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Input："I am a student."
Output: "student. a am I"

尝试使用三步反转，按空格分词，先对每个词反转再整体反转

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I am a student.
I ma a .tneduts
student. a am I
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string reverseWord(string str)
{
    stringstream ss(str);
    string tmp;
    string result;
    ss >> tmp;
    reverse(tmp.begin(), tmp.end());
    result += tmp;

    while (ss >> tmp)
    {
        reverse(tmp.begin(), tmp.end());
        result += " ";
        result += tmp;
    }
    reverse(result.begin(), result.end());
    return result;
}

1.4

in a word, 临时变量溢出

计算机对int溢出的处理

比如一个4字节的int类型1052254545

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int n = 1052254545;
int m = n * 10; //1932610858

正常情况下m应该为10522545450,但这个数的二进制位有34位，int在这里只能保存32位，所以只会保留后32位

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//10522545450
‭10 0111 0011 0011 0001 0100 1101 0010 1010‬

//1932610858
   0111 0011 0011 0001 0100 1101 0010 1010‬

1.6 Manacher算法

12212321

$#1#2#2#1#2#3#2#1#

S[i] # 1 # 2 # 2 # 1 # 2 # 3 # 2 # 1 #
P[i] 1 2 1 2 5 2 1 4 1 2 1 6 1 2 1 2 1

max(P[i] - 1)是原字符串中最长回文子串的长度

codeigniter-1

1.去除url中的index.php

Apache24/conf/httpd.conf

去除下面这行的注释

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LoadModule rewrite_module modules/mod_rewrite.so

改下下面这个部分(原来是AllowOverride None)

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# AllowOverride controls what directives may be placed in .htaccess files.
    # It can be "All", "None", or any combination of the keywords:
    #   AllowOverride FileInfo AuthConfig Limit
    #
    AllowOverride All

system同级目录下的.htaccess

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<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php/$1 [L]
</IfModule>

如果不是www或htdocs的根目录就加上项目名，如这里的tutorial

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RewriteRule ^(.*)$ /tutorial/index.php/$1 [L]

application/config/config.php

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$config['index_page'] = "";

2.js,css,images的存放路径填写

3.路由

4.出现http://[::1]

application/config/config.php下的base_url不要设置为空

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$config['base_url'] = 'http://localhost/projectname/';

$config['base_url'] = 'http://www.example.com/';
  1. 连接数据库

References

  1. https://blog.csdn.net/k8080880/article/details/77451307

  2. CI框架中base_url关于[::1]的问题