Question

我在这个while循环中遇到分段错误，我不知道为什么。该程序是一行代码计数器。 while循环用于计算类中的行数，因此只需将'{'添加到堆栈中，并在循环中出现'}'时弹出它们。当堆栈为空时，它应该退出while循环。这是while循环，后跟完整的代码..

int countObjectLines(int index){
    stack<char> symbols;
    int i = index+1;
    int numberLines = 0;        
    symbols.push('{');
    while (!symbols.empty())
    {       
        string test(code[i]);
        for(int j = 0; j < test.size(); j++){               
            if(test[j] == '{'){
                symbols.push(test[j]);
            }

            else if(test[j] == '}' && symbols.top() == '{'){
                symbols.pop();                  
            }

            else{}
            numberLines++;
        }
        i++;
    }

    return numberLines;
}

这是完整的代码。

#include <iostream>
#include <fstream>
#include <stack> 
#include <string>
#include <vector>
#include <sstream>
using namespace std;

//Lines of Code Iterator Class
class LOCitr{
public: 
    int count;
    vector<string> code;

    LOCitr()
    {
        count = 0;
    }

    ~LOCitr(){}

    //Trim White Space so line does not get counted
    string trimWhiteSpace(string const& str)
    {
        size_t first = str.find_first_not_of(' '); //find first character not a space
        if(first == string::npos) 
            return "";
        size_t last  = str.find_last_not_of(' '); //find the end of line before more whitespaces
        return str.substr(first, last-first+1); //create the string again with no white spaces
    }

    //Trim tab space from string
    string trimTab(string const& str)
    {
        size_t first = str.find_first_not_of('\t'); 
        if(first == string::npos) 
            return "";
        size_t last  = str.find_last_not_of('\t'); 
        return str.substr(first, last-first+1); //create the string again with no tab
    }

    //counter of lines
    int counter(string fileName)
    {
        string line;    
        string first_word = "";
        ifstream myfile (fileName.c_str());
        if (myfile.is_open())
        {
            while ( getline (myfile,line) )
            { 
                line = trimWhiteSpace(line);
                line = trimTab(line);
                if(line.empty()) //check for empty line
                    continue;     
                if(line[0] == '/' && line[1] == '/') //check for comment
                    continue;
                count++;
                code.push_back(line);
            }

            for (int i = 0; i < code.size(); i++){
                cout<< endl << "code["<<i<<"] "<<code[i];
                stringstream stream(code[i]);       
                stream >> first_word;
                if (first_word == "class" || first_word == "struct")
                    {
                        cout << endl << first_word << i;
                        cout << "objectLines: " << countObjectLines(i);
                    }
            }

            myfile.close();
        }
        else return 0; 



        return count;
    }

    int countObjectLines(int index){
        stack<char> symbols;
        int i = index+1;
        int numberLines = 0;        
        symbols.push('{');
        while (!symbols.empty())
        {       
            string test(code[i]);
            for(int j = 0; j < test.size(); j++){               
                if(test[j] == '{'){
                    symbols.push(test[j]);
                }

                else if(test[j] == '}' && symbols.top() == '{'){
                    symbols.pop();                  
                }

                else{}
                numberLines++;
            }
            i++;
        }

        return numberLines;
    }


};


int main () {

    int count = 0;
    string file = "";
    LOCitr countMe;
    char input = 'y';

    //while loop to keep entering files to check
    while (input == 'y'){
        cout << "Enter file name:" << "\t";
        cin >> file;

        count = countMe.counter(file);    

        cout << endl << count <<endl;

        cout << "Enter another file? Enter Y/N :" << "\t";

        cin >> input;
    }



    return 0;
}

Answer 1

您的代码似乎存在一些问题：

您的循环条件为while (!symbols.empty())，但假设代码中的大括号已正确平衡，则symbols堆栈不会变空。然后会发生什么？您将code[i]访问i超出code的有效范围。
您的计算numberLines = (j-i)+1;似乎有误，因为i用于索引行，而j用于索引列。不知道如何减去这些并获得任何有意义的东西。

Loop Keeps给出Segmentation故障

1 个答案: