在管理内存泄漏问题C++

我没有得到任何错误或类似的东西，但问题是，无论我做什么，我都无法摆脱那些内存泄漏。我发现的唯一解决方案是帮助我在每种方法之后添加delete[] vector1，但我不允许修改代码的这一部分。在代码中，您可以看到评论和我可以添加新说明的区域。有没有解决我的问题？在管理内存泄漏问题C++

这是代码：

#include<iostream> 
using namespace std; 

/*YOU CAN'T ADD NEW METHODS*/ 
/*YOU CAN ONLY MODIFY THE BODY OF THE METHODS*/ 

//read array from the console - number of elements and the elements 
int * readVectorVersion1(int * noElements) { 
    int *vector1; 
    vector1 = new int[*noElements + 1]; 
    for (int i = 0; i < *noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector1[i]; 

    } 
    return vector1; 
} 
//read array from the console - number of elements and the elements 
void readVectorVersion2(int ** vector, int* noElements) { 
    *vector = new int[*noElements + 1]; 
    for (int i = 0; i < *noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> (*vector)[i]; 
    } 
} 
//read array from the console - number of elements and the elements 
void readVectorVersion3(int *& vector, int& noElements) { 
    vector = new int[noElements + 1]; 
    for (int i = 0; i < noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector[i]; 
    } 
} 

//read array from the console - number of elements and the elements 
int * readVectorVersion4(int& noElements) { 
    int *vector1; 
    vector1 = new int[noElements + 1]; 
    for (int i = 0; i < noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector1[i]; 
    } 
    return vector1; 
} 

//read static array from the console - number of elements and the elements 
void readStaticVector(int vector[], int * noElements) { 
    for (int i = 0; i < *noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector[i]; 
    } 
} 

//print the elements of the array 
void afisareVector(int* vector, int noElements) { 
    cout << endl << "Vector:" << endl; 
    for (int i = 0; i < noElements; i++) 
     cout << vector[i] << " "; 

} 


//read a name from the console 
char* citesteNume() { 
    char temp[200]; 
    char * nume; 
    cout << endl << "Your name:"; 
    cin >> temp; 
    nume = new char[strlen(temp) + 1]; 
    strcpy(nume, temp); 

    return nume; 
} 

//read a name from the console 
void citesteNume(char* nume) { 


    cout << endl << "Your name:"; 
    cin >> nume; 


} 
//METHODS THAT ADDS AN ELEMENT (THAT IS GIVEN) TO AN EXISTING ARRAY 
//FIRST 
void adaugaElementNou(int** vector, int* noElemente, int elementNou) { 
    (*vector) = new int[*noElemente + 2]; 
    for (int i = 0; i < *noElemente; i++) 
     (*vector)[i] = i; 

    (*vector)[*noElemente] = elementNou; 

} 
//SECOND 
int * adaugaElementNou(int& noElemente, int elementNou) { 
    int *vector; 
    vector = new int[noElemente + 2]; 
    for (int i = 0; i < noElemente; i++) 
     vector[i] = i; 
    vector[noElemente] = elementNou; 
    return vector; 

} 
//THIRD 
int * adaugaElementNou(int* noElemente, int elementNou) { 
    int *vector; 
    vector = new int[(*noElemente) + 2]; 
    for (int i = 0; i < *noElemente; i++) 
     vector[i] = i; 
    vector[*noElemente] = elementNou; 
    return vector; 

} 



//THE PROGRAM MUST RUN AND NOT GENERATE ANY ERRORS OR MEMORY-LEAKS 
void main() { 
    //YOU CAN'T ADD NEW VARIABLES 

    int * vector1; 
    int vector2[50]; 
    int nrElementeVector1=3; 
    int nrElementeVector2=3; 

    //YOU CAN ADD NEW INSTRUCTIONS 
    // ... 
    vector1 = new int[nrElementeVector1 + 1]; 
    for (int i = 0; i < nrElementeVector1; i++) 
     vector1[i] = i; 
    for (int i = 0; i < nrElementeVector2; i++) 
     vector2[i] = i; 
    //YOU CAN'T MODIFY THE FOLLOWING CODE 

    afisareVector(vector1, nrElementeVector1); 
    afisareVector(vector2, nrElementeVector2); 
    //delete[]vector1; /*This instruction is added by me but i`m not allowed to modify this area of the code*/ 
    vector1 = readVectorVersion1(&nrElementeVector1); 
    afisareVector(vector1, nrElementeVector1); 
    //delete[]vector1; 
    readVectorVersion2(&vector1, &nrElementeVector1); 
    afisareVector(vector1, nrElementeVector1); 
    //delete[]vector1; 
    readVectorVersion3(vector1, nrElementeVector1); 
    afisareVector(vector1, nrElementeVector1); 
    //delete[]vector1; 
    vector1 = readVectorVersion4(nrElementeVector1); 
    afisareVector(vector1, nrElementeVector1); 
    //delete[]vector1; 
    readStaticVector(vector2, &nrElementeVector2); 
    afisareVector(vector2, nrElementeVector2); 

    char* string1; 
    char string2[50]; 

    string1 = citesteNume(); 
    cout << endl << "Hello " << string1; 
    //delete[]string1; /*THIS IS NOT ALLOWED HERE*/ 
    citesteNume(string2); 
    cout << endl << "Hello " << string2; 

    vector1 = adaugaElementNou(nrElementeVector1, 99); 
    afisareVector(vector1, nrElementeVector1+1); 
    //delete[]vector1; 
    adaugaElementNou(&vector1, &nrElementeVector1, 55); 
    afisareVector(vector1, nrElementeVector1+1); 
    //delete[]vector1; 
    vector1 = adaugaElementNou(&nrElementeVector1, 77); 
    afisareVector(vector1, nrElementeVector1+1); 
    //delete[]vector1; 

    //YOU CAN ADD NEW INSTRUCTIONS HERE 
    // ... 

    delete[] vector1; //I`ve tried to use delete here because I didn`t knew what else i should do, but I know that it makes no sense(and it`s not working); 
    delete[] string1; 

    //THE FOLLOWING CODE CHECKS IF THERE ARE ANY MEMORYLEAKS 
    _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE); 
    _CrtSetReportFile(_CRT_WARN, _CRTDBG_FILE_STDOUT); 
    _CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_FILE); 
    _CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDOUT); 
    _CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_FILE); 
    _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDOUT); 
    _CrtDumpMemoryLeaks(); 

    //YOU CAN'T MODIFY THE FOLLOWING CODE 
    vector1 = NULL; 
    string1 = NULL; 
    cout << endl << "In this moment there are no memory-leaks!"; 
}

来源

2015-11-01 Alex Chihaia

此任务是否允许修改程序的行为（预期输出）以摆脱内存泄漏？ –

这个家庭作业显然是由大约20年前学过C++的人创建的，他从来没有打算更新他的知识。 –

我想我知道该怎么做'delete [] vector1'。我会尝试和我的黑客告诉你，如果我成功了。 –

对于字符串1这很简单，你可以：

delete[] string1;

这是我认为你应该做处理向量1：

void afisareVector(int* vector, int noElements) { 
    cout << endl << "Vector:" << endl; 
    for (int i = 0; i < noElements; i++) 
     cout << vector[i] << " "; 

    // A very dirty hack, PLEASE **NEVER** USE IT. 
    static int callIndex = 0; 
    if(callIndex != 1 && callIndex != 6) 
     delete[] vector; 
    ++callIndex; 
}

的valgrind摘要：

==20937== HEAP SUMMARY: 
==20937==  in use at exit: 0 bytes in 0 blocks 
==20937== total heap usage: 9 allocs, 9 frees, 144 bytes allocated 
==20937== 
==20937== All heap blocks were freed -- no leaks are possible 
==20937== 
==20937== For counts of detected and suppressed errors, rerun with: -v 
==20937== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

编辑：我改变了主意。上面的例子是你可以做的，这是你应该做的：
注意＃1：这种黑客感觉对我来说更脏。
注意＃2：为了编译它，我必须删除所有微软特定的东西，并用valgrind执行泄漏检查。

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

/*YOU CAN'T ADD NEW METHODS*/ 
/*YOU CAN ONLY MODIFY THE BODY OF THE METHODS*/ 

//read array from the console - number of elements and the elements 
int * readVectorVersion1(int * noElements) { 
    static int vector1[50]; 
    for (int i = 0; i < *noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector1[i]; 

    } 
    return vector1; 
} 
//read array from the console - number of elements and the elements 
void readVectorVersion2(int ** vector1, int* noElements) { 
    static int vector [50]; 
    for (int i = 0; i < *noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector[i]; 
    } 
    *vector1 = vector; 
} 
//read array from the console - number of elements and the elements 
void readVectorVersion3(int *& vector1, int& noElements) { 
    static int vector [50]; 
    for (int i = 0; i < noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector[i]; 
    } 
    vector1 = vector; 
} 

//read array from the console - number of elements and the elements 
int * readVectorVersion4(int& noElements) { 
    static int vector1 [50]; 
    for (int i = 0; i < noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector1[i]; 
    } 
    return vector1; 
} 

//read static array from the console - number of elements and the elements 
void readStaticVector(int vector[], int * noElements) { 
    for (int i = 0; i < *noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector[i]; 
    } 
} 

//print the elements of the array 
void afisareVector(int* vector, int noElements) { 
    cout << endl << "Vector:" << endl; 
    for (int i = 0; i < noElements; i++) 
     cout << vector[i] << " "; 
} 


//read a name from the console 
char* citesteNume() { 
    char temp[200]; 
    char * nume; 
    cout << endl << "Your name:"; 
    cin >> temp; 
    nume = new char[strlen(temp) + 1]; 
    strcpy(nume, temp); 

    return nume; 
} 

//read a name from the console 
void citesteNume(char* nume) { 


    cout << endl << "Your name:"; 
    cin >> nume; 


} 
//METHODS THAT ADDS AN ELEMENT (THAT IS GIVEN) TO AN EXISTING ARRAY 
//FIRST 
void adaugaElementNou(int** vector, int* noElemente, int elementNou) { 
    static int vector1 [50]; 
    for (int i = 0; i < *noElemente; i++) 
     vector1[i] = i; 

    vector1[*noElemente] = elementNou; 
    *vector = vector1; 
} 
//SECOND 
int * adaugaElementNou(int& noElemente, int elementNou) { 
    static int vector [50]; 
    for (int i = 0; i < noElemente; i++) 
     vector[i] = i; 
    vector[noElemente] = elementNou; 
    return vector; 
} 
//THIRD 
int * adaugaElementNou(int* noElemente, int elementNou) { 
    static int vector [50]; 
    for (int i = 0; i < *noElemente; i++) 
     vector[i] = i; 
    vector[*noElemente] = elementNou; 
    return vector; 
} 



//THE PROGRAM MUST RUN AND NOT GENERATE ANY ERRORS OR MEMORY-LEAKS 
int main() { 
    //YOU CAN'T ADD NEW VARIABLES 

    int * vector1; 
    int vector2[50]; 
    int nrElementeVector1=3; 
    int nrElementeVector2=3; 

    //YOU CAN ADD NEW INSTRUCTIONS 
    for (int i = 0; i < nrElementeVector2; i++) 
     vector2[i] = i; 
    vector1 = vector2; 
    //YOU CAN'T MODIFY THE FOLLOWING CODE 

    afisareVector(vector1, nrElementeVector1); 
    afisareVector(vector2, nrElementeVector2); 
    vector1 = readVectorVersion1(&nrElementeVector1); 
    afisareVector(vector1, nrElementeVector1); 
    readVectorVersion2(&vector1, &nrElementeVector1); 
    afisareVector(vector1, nrElementeVector1); 
    readVectorVersion3(vector1, nrElementeVector1); 
    afisareVector(vector1, nrElementeVector1); 
    vector1 = readVectorVersion4(nrElementeVector1); 
    afisareVector(vector1, nrElementeVector1); 
    readStaticVector(vector2, &nrElementeVector2); 
    afisareVector(vector2, nrElementeVector2); 

    char* string1; 
    char string2[50]; 

    string1 = citesteNume(); 
    cout << endl << "Hello " << string1; 
    citesteNume(string2); 
    cout << endl << "Hello " << string2; 

    vector1 = adaugaElementNou(nrElementeVector1, 99); 
    afisareVector(vector1, nrElementeVector1+1); 
    adaugaElementNou(&vector1, &nrElementeVector1, 55); 
    afisareVector(vector1, nrElementeVector1+1); 
    vector1 = adaugaElementNou(&nrElementeVector1, 77); 
    afisareVector(vector1, nrElementeVector1+1); 

    //YOU CAN ADD NEW INSTRUCTIONS HERE 
    // ... 

    delete[] string1; 

    //YOU CAN'T MODIFY THE FOLLOWING CODE 
    vector1 = NULL; 
    string1 = NULL; 
}

Valgrind的输出：

==21224== HEAP SUMMARY: 
==21224==  in use at exit: 0 bytes in 0 blocks 
==21224== total heap usage: 1 allocs, 1 frees, 2 bytes allocated 
==21224== 
==21224== All heap blocks were freed -- no leaks are possible 
==21224== 
==21224== For counts of detected and suppressed errors, rerun with: -v 
==21224== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

编辑：我想出了第三个（更脏）的解决方案，但我太累了这一切的黑客编写完整的版本。下面是一个示例：

int * readVectorVersion1(int * noElements) { 
    static int *vector1 = NULL; 
    delete[] vector1; 
    if (noElements < 0) 
     return NULL; 
    vector1 = new int[*noElements + 1]; 
    for (int i = 0; i < *noElements; i++) 
    { 
     cout << endl << "Vector1[" << i + 1 << "]="; 
     cin >> vector1[i]; 

    } 
    return vector1; 
} 

// ... 

int main() { 
    // ... 
    // Just before _CrtSetReportMode 
    nrElementeVector1 = -1; 
    readVectorVersion1(*nrElementeVector1); 
    // .. 
}

来源

2015-11-01 12:48:04

if语句检查什么？你能解释给我吗？你用什么来显示内存泄漏？ –

@AlexChihaia你第二次打电话给afisareVector，第七次打电话给afisareVector时，它不能释放记忆，在所有其他地方都不能释放记忆。我只是添加了一个静态计数器来检测是否调用delete []。附：我无法找到解释静态工作原理的良好链接。 –

@AlexChihaia如果你想解释一下'static'是如何工作的，我认为[这个链接]（http://www.linuxtopia.org/online_books/programming_books/thinking_in_c++/Chapter10_002.html）会给你一些线索。另请注意：我改变了自己的想法（阅读更新后的答案）。 –

我说这个任务是不可能完成的任务。该行

vector1 = readVectorVersion1(&nrElementeVector1);

在vector1持有动态分配的资源时执行。在这一点上创建一个不可恢复的泄漏。这同样适用于以下

readVectorVersion2(&vector1, &nrElementeVector1);

来源

2015-11-01 10:58:54

的vector1指针被覆盖的，你可能不修改代码，所以显然这可能不是唯一的指向动态分配的内存，否则会泄漏并没有什么你可以在你的任务限制内做到这一点。

因此，让我们探讨使用静态对象来保存指针的可能性。为简单起见，我将使用std::vector，但如果需要，可以使用静态指针指向动态内存。在这种情况下，您需要手动管理内存。

int * readVectorVersion1(int * noElements) { 
    static std::vector<int> vector1; 
    vector1.resize(*noElements); 

    // initialize the way you want to 

    return vector1.data(); 
    // return &vector1[0]; // use this if you use older version of c++ than c++11 
}

然后你去了。内存将在静态对象被销毁时解除分配。这当然会限制你可以用这个函数做什么。您不能再分配两个单独的数组，因为随后的调用将使用相同的向量。但是这个任务不需要，所以我想这是你的老师所要求的。

来源

2015-11-01 11:17:33 user2079303

好的。我写了这段代码，并且仍然有内存泄漏（至少这是输出）。当我使用“删除[] vector1”在主程序运行，但比我得到一个错误。我做错了什么？这是代码： –

'#include #include using namespace std; int * readVectorVersion1（int * noElements）{ \t \t static vector vector1; \t vector1.resize（* noElements）; \t unsigned int i; \t //初始化要 \t的方式（I = 0; I > vector1 [i]; } \t return＆vector1 [0]; } void afisareVector（int * vector，int noElements）{ \t cout << endl <<“Vector：”<< endl; \t for（int i = 0; i

'void main（）{ \t int * vector1; \t int nrElem = 4; \t vector1 = readVectorVersion1（＆nrElem）; \t afisareVector（vector1，nrElem）; \t //删除[] vector1; \t _CrtSetReportMode（_CRT_WARN，_CRTDBG_MODE_FILE）; \t _CrtSetReportFile（_CRT_WARN，_CRTDBG_FILE_STDOUT）; \t _CrtSetReportMode（_CRT_ERROR，_CRTDBG_MODE_FILE）; \t _CrtSetReportFile（_CRT_ERROR，_CRTDBG_FILE_STDOUT）; \t _CrtSetReportMode（_CRT_ASSERT，_CRTDBG_MODE_FILE）; \t _CrtSetReportFile（_CRT_ASSERT，_CRTDBG_FILE_STDOUT）; \t _CrtDumpMemoryLeaks（）; }' –

在管理内存泄漏问题C++

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