LAB1-2

目录

guithub link

https://github.com/GTXGTA/EE308_LAB1_2

PSP table

Problem solving ideas

• File input
  • To read in a code file, we first need to figure out how to read the contents of the file.
  • I searched the Internet and learned about reading files.
• Cut the string
  • When the file is read in, it is read in line, and the string needs to be cut into individual words to detect.
  • So I should know which ones should be used as cut identifiers in c++/c files.
• Keyword detection
  • I might need an array of constants as a dictionary for my later code to look up in that dictionary.
• On switch-case detection.
  • I can use a counter to calculate.
  • When a switch occurs, it means that the previous switch structure will not appear case again, case num is listed, and the counter is reset.
  • I think the queue size should be the number of switch structures.
• On if-else and if-else if-else detection
  • When I think about it, I think there's an if-else structure or an if-else if-else structure when it ends with an else.
  • So I should use a stack to handle it.

Design and implementation process

The way I organize my code is around the Code_test class.

The key code description

• class Code_test

  • My Code_test class encapsulates the main function, cut function, keyword detection,if-else structure and if-else if-else structure with count and output functions.

  class Code_test
  {
      public:
          Code_test(){}
          bool Divide(int &index);
          void T1(string divided_unit);
          void T2(int &index);
          void T_File(string filename);
          void Display(int level);
      private:
          string str_line,word;
          int Keyword_Count;
          ifstream Infile;
          ofstream OutFile;
          stack <int> if_else_Stack;
          queue <int> switch_Queue;
          bool Is_Previous_Else;
          
          int If_else_count;
          int If_elseif_else_count;
          int Switch_Count;
  }; 
  

  • Divide function

    bool Code_test::Divide(int &index)
    {
        if(str_line[index] == '"')
        {
            int j = index;
            for(index = index + 1; index < str_line.size(); index++)
            {
                if(str_line[index] == '"') return true;
            }
            index = j;
            return true;
        }
        if(str_line[index] == '/' && str_line[++index] == '*')
        {
            for(index = index + 1; index < str_line.size(); index++)
            {
                if(str_line[index] == '*' && str_line[++index] == '/') return true;
            }
            while(getline(Infile, str_line))
            {
                for(index = 0; index < str_line.size(); index++)
                { 
                    if(str_line[index] == '*' && str_line[++index] == '/') return true;
                }        
            }
        }
        if(str_line[index] == '(' || str_line[index] == ')') return true;  
        else if(str_line[index] == '<' || str_line[index] == '>') return true;
        else if(str_line[index] == '&' || str_line[index] == '*') return true;   
        else if(str_line[index] == '{' || str_line[index] == '}') return true;  
         
        
        else if(str_line[index] == '\n'|| str_line[index] == '\0' || str_line[index] == '\t') return true;  
        else if(str_line[index] == ' ' || str_line[index] == ',' || str_line[index] == ';' || str_line[index] == ':') return true;  
        return false;
    }
    

  • T1 function

    void Code_test::T1(string divided_unit)
    {
        for(int i = 0; i < 32; i++) if(divided_unit == kKeyWordName[i]) Keyword_Count++;
        if(divided_unit == "switch" && Switch_Count)  
        {
            switch_Queue.push(Switch_Count);
            Switch_Count = 0;
        }
        if(divided_unit == "case") Switch_Count++;
        if(divided_unit == "if") 
        {
            if_else_Stack.push(-1);
            if_else_Stack.push(1);
        } 
        if(divided_unit == "else") Is_Previous_Else = true;
    }
    

  • T2 function

    void Code_test::T2(int &index)
    {
        for(index; index < str_line.size(); index++) if (!(str_line[index] == ' ' || str_line[index] == '\t')) break;
        if(index == str_line.size())
        {
            int flag = 0;
            while (getline(Infile, str_line))
            {
                for(index = 0; index < str_line.size(); index++)
                {
                    if (!(str_line[index] == ' ' || str_line[index] == '\t'))
                    {
                        flag = 1;
                        break;
                    }
                }
                if(flag) break;
            }    
        } 
        if(str_line[index] == 'i' && str_line[index+1] == 'f') 
        {
            if_else_Stack.push(1);
            index++;
            Keyword_Count++;
        }
        else
        {
            int ifelse_stack_count_ = 0;
            while(if_else_Stack.top() > 0 && !if_else_Stack.empty())
            {
                ifelse_stack_count_ += if_else_Stack.top();
                if_else_Stack.pop();
            }
            if(ifelse_stack_count_ > 1) If_elseif_else_count++;
            else if(ifelse_stack_count_ == 1) If_else_count++;
        }                
    }
    

Unit test

Below are the unit test results for levels 1,2,3, and 4, respectively.

• Level 1 unit test results.

  

• Level 2 unit test results.

  

• Level 3 unit test results.

  

• Level 4 unit test results.

  

Performance Optimization Analysis

As you can see from the figure below, the functions that occupy more resources are Divide function,T1 function,T_File function.

Summarize

• Learning and Gain
  • In this practice, I learned to master some usage methods of github and csdn, and consolidated my markdown related syntax, so that I am more skilled in using them.
  • At the same time, I also practice the keyword detection of c++, for the programming, the if_else judgment, and the string cutting problem all let me benefit a lot.
• Difficulties encountered and solutions
  • Very inexperienced with github
    • I tried to learn the related use methods of github on the Internet, and spent time simply learning and understanding some basic use methods of github.
  • Programming problems
    • When writing the c++ keyword recognition program, I have a lot of doubts about the method of identifying keywords. In the case of searching information online and asking surrounding students, I basically understand the solution and ideas. At the same time, I encountered many errors when trying to write the code. After my careful elimination, I successfully solved the problems I encountered.