找不到细分错误的来源

时间:2020-04-20 08:47:50

标签: c++ segmentation-fault

一段时间以来,我一直在从事这项工作,但无法弄清楚是什么原因造成了分段错误,我们将不胜感激,这是我的两个文件的副本!

我也正在修复inFile设置,但是在出现分段错误之后,我宁愿专注于此。

#include <iostream>
#include <fstream>
#include <string>
#include <list>
#include "source.cpp"

using namespace std;
void scanFile(string fileName);
void printActors(string movie);
void printShows(string actor);

const int MAX_LINE = 128;
int movies = 0;
BST tree;

int main(){
    // Scan file
    scanFile("tvDB.txt");

    // Print all the show titles
    cout << "All show titles:" << endl;
    tree.displayShows();
    cout << endl; // Whitespace


    // Print actors /w given show
    cout << "Actors from 'The Saint'" << endl;
    printActors("The Saint");


    // Print show  /w given actor
    printShows("Tim Conway");


    // Print from decade


    return 0;
}

// Trims the line removing all excess whitespace before and after a sentence
string isolateLine(string line)
{
    int index = 0, start = 0, end = 0;

    //Get the start of the line
    for(int i = 0; i < line.length(); i++)
    {
        if(line[i] != ' ' && line[i] != '\t')
        {
            start = i;
            break;
        }
    }

    // Get the end of the line
    for(int x = line.length(); x >= 0; x--)
    {
        if(line[x] != ' ' && line[x] != '\t')
        {
            end = x;
            break;
        }
    }

    // Trim line
    line = line.substr(start, end);
    return line;
}

// A boolean that returns if the tree is blank, useful for skipping a line and continuing to search for a movie
bool blankLine(string line){
    for(int i = 0; i < line.length(); i++)
    {
        if(line[i] != ' ' && line[i] != '\t')
        {
            return false;
        }
    }
    return true;
}

// Prints all the shows an actor has starred in
void printShows(string actor){
    cout << "Shows with [" << actor << "]:" << endl;
    tree.displayActorsShows(actor);
    cout << endl; // whitespace
}

// Prints all the actors in a particular movie
void printActors(string show)
{
    cout << " Actors for [" << show << "]" << endl;
    tree.displayActors(show);
    cout << endl;
}

// Scans the fild and categorizes every line of data into the proper categories of the show
void scanFile(string fileName)
{
    ifstream inFile;
    inFile.open("tvDB.txt");
    list <string> actors;

    string line = "";
    string title = "";
    string year = "";

    while(getline(inFile, line))
    {
        line = isolateLine(line);

        if(!blankLine(line))
        {
            // Get movie title
            if(line.find('(') != std::string::npos)
            {
                title = line.substr(0, line.find('(')-1);
            }

            // Get movie year
            if (line.find('(') != std::string::npos) {
                year = line.substr(line.find('(') + 1, line.find(')'));
                year = year.substr(0, year.find(')'));
            }

            // Add to actors list
            actors.push_back(line);
        }
        else
        {
            if(!actors.empty()) // pops the title
            {
                actors.pop_front(); 
            }
        }
        tree.insert(title, year, actors);
        actors.clear();
        movies++;
    }
}

#include <iostream>
#include <list>
using namespace std;

class BST
{
    // Defines the main components of the node object, as well as refrences the left and right elements
    struct node
    {
        string show;
        string year;
        string genre;
        string URL;
        list <string> actors;
        node*left;
        node*right;
    };

    node* root;

    // Deletes all the nodes of the tree
    node* makeEmpty(node* t)
    {
        if(t == NULL)
        {
            return NULL;
        }
        else
        {
            makeEmpty(t->left);
            makeEmpty(t->right);
            delete t;
        }
        return NULL;
    }

    // Inserts a node in the tree
    node* insert(string x, string year, list<string> actors, node* t)// DO not include Genrem or URL
    {
        if(t == NULL)
        {
            t = new node;
            t->show = x;
            t->year = year;
            t->actors = actors;
            t->left = t->right = NULL;
        }
        else if(x < t-> show)
        {
            t->left = insert(x, year, actors, t->left);
        }
        else if(x > t-> show)
        {
            t->right = insert(x, year, actors, t->left);
        }
        else
        {
            return t;
        }
    }

    //Finds the minimum most node to the left
    node* findMin(node* t)
    {
        if(t == NULL)
        {
            return NULL;
        }
        else if(t->left == NULL)
        {
            return t;
        }
        else
        {
            return findMin(t->left);
        }
    }

    // Finds the maximum most node to the right
    node* findMax(node* t)
    {
        if(t == NULL)
        {
            return NULL;
        }
        else if(t->right == NULL)
        {
            return t;
        }
        else
        {
            return findMax(t->right);
        }
    }

    // Finds a node with the given parameters
    node* find(node* t, string x )
    {
        if(t == NULL)
        {
            return NULL;
        }
        else if(x.at(0) < t-> show.at(0))
        {
            return find(t->left, x);
        }
        else if(x.at(0) > t->show.at(0))
        {
            return find(t->right, x);
        }
        else
        {
            return t;
        }
    }

    // Prints out the shows inorder
    void inorder(node* t)
    {
        if(t == NULL)
        {
            // Do nothing
        }
        else
        {
            inorder(t->left);
            cout << "- " << t->show << endl;
            inorder(t->right);
        }
    }

    // Prints the shows of a given actor
    void findShow(node* t, string person, list<string> &list)
    {
        if(t == NULL)
        {
            // Do nothing
        }
        else
        {
            while(!t->actors.empty())
            {
                if(t->actors.front() == person)
                {
                    list.push_front(t->show);
                    break;
                }
                t->actors.pop_front();
            }
            findShow(t->left, person, list);
            findShow(t->right, person, list);

        }
    }

    // Prints the shows within a given year
    void findYear(node* t, string year, list<string> &list)
    {
        if(t == NULL)
        {
            // Do nothing
        }
        else
        {
            if(t->year == year)
            {
                list.push_front(t->show);
            }
            findYear(t->left, year, list);
            findYear(t->right, year, list);
        }

    }
public:
    BST()
    {
        root = NULL;
    }

    ~BST()
    {
        root = makeEmpty(root);
    }

    // Public calls to modify the tree

    // Inserts a node with the given parametersremove
    void insert(string x, string year, list<string> actors)
    {
        root = insert(x, year, actors, root);
    }

    // Removes a node with the given key
    // void remove(string x, node* t)
    // {
    //     root = remove(x, root);
    // }


    // Displays all shows within the tree
    void displayShows()
    {
        inorder(root);
    }

    // Displays all the actors with a given show
    void displayActors(string show)
    {
        root = find(root, show);
        if(root != NULL) // THIS LINE
        {
            list<string> temp = root-> actors;
            while(!temp.empty())
            {
                cout << "- " << temp.front() << endl;
                temp.pop_front();
            }
        }
        else 
        {
            cout << "root is NULL." << endl;
        }
    }

    // Displays the shows of a given actor
    void displayActorsShows(string actor)
    {
        list<string> show;
        findShow(root, actor, show);
        while(!show.empty())
        {
            cout << "- " << show.front() << endl;
            show.pop_front();
        }
    }

    // Searches the tree with the given node
    void search(string x)
    {
        root = find(root, x);
    }
};// end of class

1 个答案:

答案 0 :(得分:2)

我建议使用调试器(例如用于Unix的GDB或VisualStudioBuildIn调试器)。 SEG Fault在那里指示段故障将在哪个变量中。 还要注意正确的初始化指针(至少使用= nullptr

顺便说一句:尝试使用nullptr而不是NULL,因为使用NULL类型不安全。 原因如下:NULL vs nullptr (Why was it replaced?)