ARTS第九周打卡

Algorithm : 做一个 leetcode 的算法题

/*

  两数之和
给定一个整数数组 nums 和一个目标值 target，请你在该数组中找出和为目标值的那 两个 整数，并返回他们的数组下标。

你可以假设每种输入只会对应一个答案。但是，你不能重复利用这个数组中同样的元素。

示例:

给定 nums = [2, 7, 11, 15], target = 9

因为 nums[0] + nums[1] = 2 + 7 = 9
所以返回 [0, 1]

*/

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        unordered_map<int, int> stTmpMap;
        vector<int> vect;
         
        // 时间复杂度O(n),空间复杂度O(n)
        for(int i = 0; i < (int)nums.size(); i++)
        {
            int iComplement = target - nums[i];
            if(stTmpMap.find(iComplement) != stTmpMap.end())
            {
                vect.push_back(stTmpMap[iComplement]);
                vect.push_back(i);
                // break;  // 如果只有一对符合要求！！！
            }
            stTmpMap[nums[i]] = i;
        }
        
        return vect;
    }
};

Review : 阅读并点评一篇英文技术文章

原文链接：https://dev.mysql.com/doc/refman/8.0/en/data-types.html

MySQL supports a number of SQL data types in several categories: numeric

types, date and time types, string (character and byte) types, spatial types, and

the JSON data type.

MYSAL支持多种数据类型：数字类型、时间和日期类型、字符串(字符和字节)类型、空间类型和JSON数据类型；

This chapter provides an overview（概述） of these data types, a more detailed

description of the properties of the types in each category, and a

summary of the data type storage requirements. The initial overview is

intentionally brief. The more detailed descriptions later in the chapter should be

consulted for additional information about particular data types, such as the

permissible formats in which you can specify values.

Data type descriptions use these conventions:（数据约定）

• For integer types, M indicates the maximum display width. For floating-point and fixed-point types, M is the total number of digits that can be stored (the precision). For string types, M is the maximum length. The maximum permissible value of M depends on the data type.

对于整数类型，M表示最大显示宽度；对于浮点型和定点型，M是可存储的位数(精度)；对于字符串类型，M是最大长度，M的最大允许值取决于数据类型。   

• D applies to floating-point and fixed-point types and indicates the number of digits following

• the decimal point (the scale). The maximum possible value is 30, but should be no greater than M−2.

• fsp applies to the TIME, DATETIME, and TIMESTAMP types and represents fractional seconds precision; that is, the number of digits following the decimal point for fractional parts of seconds. The fsp value, if given, must be in the range 0 to 6. A value of 0 signifies that there is no fractional part. If omitted, the default precision is 0. (This differs from the standard SQL default of 6, for compatibility with previous MySQL versions.)

• Square brackets ([ and ]) indicate optional parts of type definitions.

Tips : 学习一个技术技巧

基于数组和链表实现的内存管理器实现

https://www.cnblogs.com/yzdai/p/11442172.html

Share : 分享一篇有观点和思考的技术文章

Lua学习：https://blog.csdn.net/qq_35718410/article/details/52767518