c++ - 在哪里删除动态内存 “char p”？

Question

这是一个子手游戏程序。我在主中声明了一个char * p，我不明白为什么我在以后不需要时无法在程序中删除它。我稍后尝试删除它，但它给出了堆内存错误。
另外，我还是c++的新手-实际上是编程方面的人-如果您能在如何使该程序(控制台上)的输出看起来更具吸引力和交互性方面提供帮助，我也将不胜感激。就像我应该在哪里使用system(“cls”)命令一样，可以使它看起来更具可读性并删除不必要的信息。在程序的同一目录中创建一个文件，名称为easy，medium或hard。这样，当您运行程序时它便可以从中输入信息。

#pragma once    
#include<iostream>
#include<string>
#include<ctime>
#include <cstdlib>
#include <stdlib.h>
#include <Windows.h>  
#include<fstream>
#include<ctime>
#include <chrono> // for measuring time
using namespace std;
using namespace chrono;

//scoring the game with recard to time....
// filing : user name unique id and all that
//storing the name of user , his score, long story short, make a record of every user who passes by
int len = 0, letterCount = 0, size = 0, guesses = 6;

class tstamp
{
    time_point<system_clock>tstart;
    time_point<system_clock>tstop;
public:
    void start()
    {
        tstart = system_clock::now();
    }
    void stop()
    {
        tstop = system_clock::now();
    }
    long long elasped()
    {
        return duration_cast<chrono::seconds>(tstop - tstart).count();
    }
};

int checkWin(string a, char *p)
{
    int count = 0;
    int i = 0;
    char *an = new char[a.length()];


    string word = p;

    for (i = 0; i < a.length(); i++)
    {
        if (a[i] == word[i])
            count++;

    }
    if (count == i)
        return 1; // 1 means the array is equal to the string  == win
    else
        return 0;  // not win
    delete[]an; // using delete here for 1st
}
void resetData(string nameOfPlayer)
{
    ofstream fout;
    fout.open(nameOfPlayer + ".txt", ios::trunc);
    //fout << "No Record";
    fout.close();


}



void playerDetails(string nameOfPlayer, string a, bool status, float timeTaken)
{
    char check = '\0';


    ofstream fout;
    fout.open(nameOfPlayer + ".txt", ios::app);
    if (status == true)
        fout << "Status : WON" << endl;
    else
        fout << "Status : LOST" << endl;
    fout << "Word : " << a << endl;
    fout << "Time taken to guess : " << timeTaken << " seconds" << endl;
    fout << "********************************************";
    fout << endl << endl;
    fout.close();
}

string * grow(string *p, string temp)  // to regrow the string array!!!!!
{
    string* newArray = new string[size + 1];
    for (int i = 0; i<size - 1; i++)
    {
        *(newArray + i) = *(p + i);

    }

    newArray[size - 1] = temp;
    delete[] p;
    return newArray;
}

char inGameMenu(char reset)
{
    reset = '\0';
    cout << "\n\t--->To reset your record press 'r' : ";
    cout << "\n\n\t--->To display your previous record press 'd' :  ";
    cout << "\n\n\t--->To continue press 'x' : ";
    cout << "\n\n\t--->To Exit the game press 'q' : ";
    cout << endl << "\n\n\t--->Your Choice : ";
    cin >> reset;
    return reset;


}

string provideWord(string *contents, string a)
{
    srand(time(NULL));
    int i = rand() % size;
    a = contents[i];
    return a;
}

string* read(string fileName, string contents[])
{
    string ext = ".txt";
    fileName = fileName + ext;
    fstream fin;
    fin.open(fileName);
    if (fin.is_open())
    {

        fin >> contents[0];
        size++;
        string temp;
        while (fin >> temp)
        {
            size++;
            contents = grow(contents, temp);
        }
    }
    else
        cout << "\n\tFile Not Found\n\n\n";
    return contents;
}

char * makeAsterisks(string temp)   // this will make astericks of the word player have to guess.
{
    int len = temp.length();
    char*p = new char[len];
    for (int i = 0; i < len; i++)
    {
        p[i] = '-';
    }
    p[len] = '\0';
    return p;
}

void displayRecord(string fileName, string display)
{
    fstream fout;
    fout.open(fileName + ".txt");
    cout << "\n----------------------------------------------------------------------------------------------------------------";
    if (fout.is_open())
    {
        cout << endl << endl;
        while (getline(fout, display))
            cout << display << endl;
    }
    else
        cout << "\n!!No Record Found!!\nYou might be a new user\n";
    cout << "\n----------------------------------------------------------------------------------------------------------------\n";
    fout.close();
}


char * checkMyGuess(string word, char userGuess, char ar[])
{
    bool flag = true;
    for (int i = 0; i < word.length(); i++)
    {
        if (userGuess == word[i])
        {
            flag = false;
            ar[i] = userGuess;
            letterCount++;
        }
    }
    if (flag == true)
    {
        _beep(450, 100);
        cout << "\n\t!!!Wrong!!!\n";
        len--;
        guesses--;
    }
    return ar;
}
void rules()
{
    system("Color 09 "); // for color effects

    cout << "\n\n\t\t\t=====================\n";
    cout << "\t\t\t||\tHANGMAN\t    ||\n\t\t\t||\tRules\t    ||"
        << "\n " << "\t\t\t=====================\n\n\n";
    _beep(4000, 500);

    system("Color 08 ");  // for color effects
    system("Color 07 "); // for color effects

    cout << "\t--> Computer will think of a word and you have try\n"   // rules
        << "\t to guess what it is one letter at a\n"
        << "\t time. Computer will draw a number of dashes \n "
        << "\tequivalent to the number of letters in the word.\n "
        << "\t If you suggest a letter that occurs\n "
        << "\t in the word, the computer will fill in the blank(s)\n"
        << "\t with that letter in the right place(s).\n"
        << "\t The session will be timed. \n\n";

    cout << endl;
    cout << "\t--> Total number of wrong choices : 6\n\n";  //wrong turns
    cout << "\t--> Objective : Guess the word / phrase before you run out of choices!\n\n";   // obj



}
int checkForName(string fileName)
{
    fileName = fileName + ".txt";
    char line = '\0';
    fstream fin;
    char fromFile[7] = "\t\tName";
    fin.open(fileName);

    int i = 0,
        check = 0;
    while (fin.get(line) && i < 7)
    {
        if (line == fromFile[i++])
            check++;
    }
    if (check == i - 1)
        return 1;
    else
        return 0;
    fin.close();

}
void checkForRecord(string fileName)
{
    fileName = fileName + ".txt";
    char line = '\0';
    fstream fin;
    char fromFile[7] = "No";
    fin.open(fileName);

    int i = 0,
        check = 0;
    while (fin.get(line) && i < 3)
    {
        if (line == fromFile[i++])
            check++;
    }
    if (check == i - 1)
    {
        fin.open(fileName, ios::trunc);
        fin.close();
    }

    fin.close();

}
int menu(int mode) // this function asks the user to enter the difficulty level of the game!!! You can't even beat medium!
{
    system("cls");
    cout << "Please select the Level of Game :\n";
    cout << "1. Easy" << endl;
    cout << "2. Medium" << endl;
    cout << "3. Hard" << endl << endl;
    cout << "Your Choice : ";
    cin >> mode;
    while (!(mode <= 3 && mode >= 1))
    {
        cout << endl << endl;
        cout << "Please Enter the number of given choices: ";
        cin >> mode;

    }
    return mode;
}
int comMenu(string nameOfPlayer, char reset)
{
    string readData;
    reset = '\0';
    while (1)
    {

        reset = inGameMenu(reset);
        if (reset == 'r')
        {
            resetData(nameOfPlayer);

            system("cls");
            Sleep(1);
        }
        else if (reset == 'd')
        {
            system("cls");
            Sleep(1);  // just to add a little delay!
            cout << "Your Record Shows :--->\n";
            displayRecord(nameOfPlayer, readData);
        }
        else if (reset == 'x')
            break;
        else if (reset == 'q')
            break;
        else
        {
            cout << "\n\n!!!Invalid Choice!!!\n\n";
        }
    }
    return reset;
}


int main()
{

    string nameOfPlayer;
    char anyKey = '\0';
    string name;
    cout << endl;

    rules();

    cout << "Enter the name of player: ";
    cin >> nameOfPlayer;



    while (1)
    {

        char reset = '\0';
        reset = comMenu(nameOfPlayer, reset);

        if (reset != 'q')  // check to exit the game
        {

            int uniquevar = checkForName(nameOfPlayer);
            if (uniquevar != 1)
            {
                ofstream fout;
                fout.open(nameOfPlayer + ".txt", ios::app);
                fout << "\t\tName of Player : " << nameOfPlayer << endl << endl << endl;   
                fout.close();
            }
            while (1)
            {
                system("Color E0");
                bool status = true; //initially win
                size = 0,
                    len = 0,
                    letterCount = 0,
                    guesses = 6;
                string a = ""; // it holds the word
                string *contents = new string[1];
                string name = "";
                char b;
                int mode = 0;
                tstamp ts;
                bool notRepeat[26] = { 0 };
                if (anyKey == 'X' || anyKey == 'x')
                    break;
                else
                {
                    mode = menu(mode);
                    if (mode == 1)
                        name = "easy";
                    else if (mode == 2)
                        name = "medium";
                    else if (mode == 3)
                        name = "hard";

                    contents = read(name, contents);
                    cout << endl;

                }
                a = provideWord(contents, a);
                delete[]contents;

                len = a.length();
                char *p = makeAsterisks(a);  // detele it later
                cout << "Total number of words to guesses: " << len << endl << endl;
                cout << "Total guesses you have: 6\n";
                cout << "Word :\n\n\t" << p << endl << endl;
                ts.start(); // it starts counting the time...
                while (guesses != 0)
                {
                    cout << "Enter char: ";
                    cin >> b;
                    if (b >= '1' && b <= '9')
                    {
                        cout << "\n\nThere is not number in the given word\n\n";
                        continue;
                    }
                    int temp = b - 97; //  it assigns the value of alphabet to temp i.e a=0,b=0 so on...

                    if (notRepeat[temp] != false)
                    {
                        cout << "\n\nYou've already used this word\n\n";
                        cout << "Remaining Choices: " << guesses << endl << endl;
                        continue;
                    }
                    else
                    {
                        p = checkMyGuess(a, b, p);
                        int checkingTheWin = checkWin(a, p);
                        if (checkingTheWin == 0)
                        {
                        }
                        else
                        {
                            cout << "\n\n\t*************You Won****************\n\n";
                            status = true; //true = win
                            break;
                        }
                        notRepeat[temp] = true;

                        cout << endl << endl;
                        cout << "Remaining Choices: " << guesses << endl;
                        cout << endl << '\t' << p << endl;
                    }
                }
                ts.stop();
                cout << "Time Taken: " << ts.elasped() << " seconds\n\n";
                p = NULL;
                if (guesses == 0)
                {
                    status = false; //false = lose
                    checkForRecord(nameOfPlayer);
                    playerDetails(nameOfPlayer, a, status, time); // right here it will create a file with the name of user
                    cout << "\n\nGame Over!!!\n\n";
                    cout << "\t\tThe word was \n\t\t\" " << a << "\"\n\n";
                }
                else
                {
                    checkForRecord(nameOfPlayer);
                    playerDetails(nameOfPlayer, a, status, time); // right here it will create a file with the name of user
                }
                
                break;

            }  //ending block of while(1) first
            system("color 07");  // shashka!!
        }

        if (reset == 'q') // to exit the game if the user decides so right away!!
            break;
    }
    
    cout << "Exiting the Game\n\n";
    _beep(3000, 500);  // ending sound!
    return 0;
}

Answer 1

在makeAsterisks中，您不允许使用空终止符。您需要再分配一个字符

char * makeAsterisks(string temp) 
{
    int len = temp.length();
    char*p = new char[len + 1]; // <-- change here
    for (int i = 0; i < len; i++)
    {
        p[i] = '-';
    }
    p[len] = '\0';
    return p;
}

话虽如此，您已经在使用 string，为什么不让自己的生活更轻松并在任何地方使用它呢？这是 makeAsterisks重写为使用 string。

string makeAsterisks(string temp) 
{
     return string(temp.length(), '-');
}