c++ - 为什么这个c++代码在Linux中可以正常运行，但在Windows中却不能

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已关闭 8 年前。

奥 git _a

我是一名 C++ 学生，陷入困境。我的代码看起来可以正常工作(嗯，我已经完成的部分)，但是内存分配中的某些内容在 Windows 7 中出现了问题，但在我运行 ubuntu 的老式笔记本电脑中却没有。当然，代码是在Windows 7上编译和测试的。

我将发布整个代码，以便您可以编译它并尝试突出显示堵塞的相关部分。该代码旨在打开一个文件，将文件解析为二维数组，然后使用该数组填充其他一些需要按年份查找最大值的数组，依此类推。

代码后面是用于填充 mainArray 的文本文件，称为“Energy.dat”。如果有必要，我还可以上传 .doc 文件以充分解释这一切背后的目的。要点是，文件中的不同列是不同类型的能量，列索引对应于数组“types[]”中的值。我需要将多个列求和到单独的数组“fossilArray”、“renewableArray”和“totalArray”中。其中，在 Windows 7 中，偶尔会充满垃圾值(即 4.3e206)，并且不同计算机上的值不同。发生这种情况的地方会在评论中显示。

我问过我的教授，他认为这是操作系统的问题。这似乎是正确的，但我缺乏解决它的知识和理解。任何输入都会有帮助。

#include <iostream>
#include <cstdlib>
#include <fstream>
#include <iomanip>
#include <cmath>
#include <string>
//#include <windows.h>
using namespace std;

void drawLine();
int returnMaxIndex(double mainArray[][14], int j);
int returnMaxIndex(double array[]);

int main()
{
    string yearString; char answer = '@'; char Eanswer = '@';   //initialize to a value to get inside while loop

    long int year = 1979;                   //same thing here

    int i, j;
    double temp;

    double mainArray[29][14];  //EVERY VALUE LOADS PERFECTLY
    double fossilArray[29];  //index 9, 12, 13 get junk values
    double renewableArray[29]; //also gets occasional junk values
    double totalArray[29];     //same here

    string types[14] = {"Year", "Coal", "Petroleum", "Natural Gas", "Other Gases", "Nuclear",
                            "Hydroelectric (pumped storage)", "Hydroelectric", "Biomass-Wood",
                             "Biomass-Other", "Geothermal", "Solar", "Wind", "Other"};

    ifstream file("Energy.dat");

    if(file.fail())
        return -1;

    for(i = 0; i < 29; i++)         //load main array
        for(j = 0; j < 14; j++)
            file >> mainArray[i][j];

    for(i = 0; i < 29; i++)         //load fossil sum array
        for(j = 1; j < 5; j++)
            fossilArray[i] += mainArray[i][j];

    for(i = 0; i < 29; i++)         //load renewable energy array
        for(j = 6; j < 13; j++)
            renewableArray[i] += mainArray[i][j];

    for(i = 0; i < 29; i++)         //load total energy array
        for(j = 1; j < 14; j++)
            totalArray[i] += mainArray[i][j];

//  for(int i = 0; i < 29; i++)
//  {   for(int j = 0; j < 14; j++)
//          {cout << fixed << setprecision(0) << setw(10) << mainArray[i][j] << " ";    if(j == 6) cout << endl;}
//      cout << endl << endl;}

//  for(i = 0; i < 29; i++)
        cout << setw(20) << std::right << fixed << fossilArray[12] << endl;

    cout << "A. Shows the energy output for a year you select between 1980 and 2008"<< endl
        << "B. Gives you the year in which each form of energy has its peak output" << endl
        << "C. Create an excel compatible output file for the total of a type of energy \n\tOR as a percentage by year" << endl;


    while (static_cast<int>(answer) < 65 || (static_cast<int>(answer) > 67 && static_cast<int>(answer) < 97) || static_cast<int>(answer) > 99)
    {
        cout << "Please choose an option A, B, or C: ";
        cin.get(answer);
    }
    drawLine();
    switch(answer)
    {
        case 'A': case 'a':
        {
            cout << "Enter the year in which you want to see the energy output(1980 - 2008): ";
            while(year < 1980 || year > 2008)
            {
                cout << endl;
                getline(cin, yearString);
                year = strtol(yearString.c_str(), NULL, 10);

            }

            drawLine();

            if(year == 1980) i = 0; if(year == 1981) i = 1; if(year == 1982) i = 2; if(year == 1983) i = 3; if (year == 1984) i = 4; if(year == 1985) i = 5;
            if(year == 1986) i = 6; if(year == 1987) i = 7; if(year == 1988) i = 8; if(year == 1989) i = 9; if (year == 1990) i = 10; if(year == 1991) i = 11;
            if(year == 1992) i = 12; if(year == 1993) i = 13; if(year == 1994) i = 14; if(year == 1995) i = 15; if (year == 1996) i = 16; if(year == 1997) i = 17;
            if(year == 1998) i = 18; if(year == 1999) i = 19; if(year == 2000) i = 20; if(year == 2001) i = 21; if (year == 2002) i = 22; if(year == 2003) i = 23;
            if(year == 2004) i = 24; if(year == 2005) i = 25; if (year == 2006) i = 26; if(year == 2007) i = 27; if(year == 2008) i = 28;

            cout << "The energy produced in the year " << year << " was...(in megawatt hours)   % of total" << endl;
            for (j = 1; j < 14; j++)
            {
                double temp = mainArray[i][j]; double temp2 = totalArray[i];
                cout << setw(36)<< std::left << types[j]  << fixed << setprecision(3) << std::right << setw(16) << mainArray[i][j] << "     " << setprecision(3) << (temp*1.0/temp2)*100.0 << endl;
                //(abs(mainArray[i][j]))/(totalArray[j])
            }
            drawLine();


        }break;

        case 'B': case 'b':
        {
            cout << "A. Coal  B. Petroleum  C. Natural Gas  D. Other Gas  E. Nuclear" << endl
                << "F. Hydro Pumped Storage  G. Hydroelectric  H. Biomass-wood" << endl;
                drawLine();
            cout << "I. Biomass-waste  J. Geothermal  K. Solar  L. Wind  M. Other energy" << endl
                <<"N. All fossil fuels  O. All renewable  P. Grand total" <<endl;
            drawLine();

            cout << "Enter the type of energy you want to see the the peak output year: ";
            while(static_cast<int>(Eanswer) < 65 || (static_cast<int>(Eanswer) > 80  && static_cast<int>(Eanswer) < 97) || static_cast<int>(Eanswer) > 112)
            {
                cin.get(Eanswer);
            }
            switch(Eanswer)
            {
                case 'A': case 'a': j = 1; break; case 'B': case 'b': j = 2; break; case 'C': case 'c': j = 3; break; case 'D': case 'd': j = 4; break;
                case 'E': case 'e': j = 5; break; case 'F': case 'f': j = 6; break; case 'G': case 'g': j = 7; break; case 'H': case 'h': j = 8; break;
                case 'I': case 'i': j = 9; break; case 'J': case 'j': j = 10; break; case 'K': case 'k': j = 11; break; case 'L': case 'l': j = 12; break;
                case 'M': case 'm': j = 13; break; case 'N': case 'n': j = 14; break; case 'O': case 'o': j = 15; break; case 'P': case 'p': j = 16; break;
            }
            if(j > 0 && j < 14)
            {
                i = returnMaxIndex(mainArray, j);
                cout << "The year of maximum energy production for " << types[j] << " is " << mainArray[i][0];
            }
            if(j == 14)
            {
                i = returnMaxIndex(fossilArray);
                cout << "The year of maximum energy production for fossil fuels is " << mainArray[i][0];
            }
            if(j == 15)
            {
                i = returnMaxIndex(renewableArray);
                cout << "The year of maximum energy production for renewable energy is " << mainArray[i][0];
            }
            if(j == 16)
            {
                i = returnMaxIndex(totalArray);
                cout << "The year of maximum energy production for total energy production is " << mainArray[i][0];
            }
        }
        break;

        case 'C': case 'c':
        break;

    }
}

int returnMaxIndex(double array[])
{
    double temp = array[0];
    for(int i = 0; i < 29; i++)
    {
        if(temp < array[i])
            temp = array[i];
    }
    cout << temp << endl;
    for(int i = 0; i < 29; i++)
    {
        if (temp == array[i])
            return i;
    }
}


int returnMaxIndex(double mainArray[][14], int j)
{
    int k = 0;
    double temp = labs(mainArray[k][j]);
    for(int i = 1; i < 29; i++)
    {
        if(temp < labs(mainArray[i][j]))
            temp = labs(mainArray[i][j]);
    }
    for(int i = 0; i < 29; i++)
    {
        if (temp == labs(mainArray[i][j]))
            return i;
    }
}

void drawLine()
{
    cout << "---------------------------------------------------------------------------" << endl;
}

Energy.dat 的内容

1980  1161562368  245994189  346239900        0  251115575         0  276020970    275366    157797   5073079       0         0        0
1981  1203203232  206420775  345777173        0  272673503         0  260683544    245201    122628   5686163       0         0        0
1982  1192004204  146797490  305259749        0  282773248         0  309212893    195940    124979   4842865       0         0        0
1983  1259424279  144498593  274098458        0  293677119         0  332129735    215867    162745   6075101       0      2668        0
1984  1341680752  119807913  297393596        0  327633549         0  321150245    461411    424540   7740504    5248      6490        0
1985  1402128125  100202273  291945965        0  383690727         0  281149418    743294    639578   9325230   10630      5762        0
1986  1385831452  136584867  248508433        0  414038063         0  290844099    491509    685234  10307954   14032      4189        0
1987  1463781289  118492571  272620803        0  455270382         0  249694973    783088    693941  10775461   10497      3541        0
1988  1540652774  148899561  252800704        0  526973047         0  222939683    935986    738258  10300079    9094       871        0
1989  1562366197  159004961  297295127   454066  529354717         0  269189209   5582109   7742914  14593443  250601   2112043   282046
1990  1572108922  118863929  309486351   621112  576861678  -3507741  289753124   7032446  11499927  15434271  367087   2788600    11913
1991  1568845635  112798164  317773359   719074  612565087  -4541435  286019443   7735675  13853928  15966444  471765   2950951   402581
1992  1597713819   92237912  334274122  1212475  618776263  -4176582  250015684   8491095  15923885  16137962  399640   2887523   479806
1993  1665464154  105425325  342221829   966508  610291214  -4035572  277523663   9151852  16223338  16788565  462452   3005827   407651
1994  1666276091   98676618  385689325  1092023  640439832  -3377825  254004826   9232281  16983843  15535453  486622   3447109   239129
1995  1686056319   68145851  419178592  1926832  673402123  -2725131  305410435   7596774  17985777  13378258  496821   3164253   213275
1996  1771972991   74782864  378757294  1341140  674728546  -3088078  341158836   8386379  17816200  14328684  521205   3234069   201222
1997  1820761761   86479050  399595822  1533366  628644171  -4039905  350647962   8680229  18484565  14726102  511168   3288035    62807
1998  1850193304  122211090  449292578  2314896  673702104  -4467280  317866620   8608130  19233174  14773918  502473   3025696   158942
1999  1858617724  111539127  472995956  1606583  728254124  -6096899  314663058   8960705  19493050  14827013  495082   4487998   138942
2000  1943111290  105192123  517977999  2027956  753892940  -5538860  271337693   8916073  20307087  14093158  493375   5593261   124885
2001  1882826136  119148891  554939683   585791  768826308  -8823445  213749291   8293796  12944430  13740501  542755   6737332  6541565
2002  1910612813   89733266  607683246  1969851  780064087  -8742928  260491387   9009328  13145020  14491310  554831  10354279  9091465
2003  1952713826  113697198  567303392  2647093  763732695  -8535065  271511659   9527678  13807633  14424231  534001  11187467  8607470
2004  1957187710  114678307  627171620  3568233  788528387  -8488210  265063848   9736404  13061787  14810975  575155  14143741  8322440
2005  1992053878  116481854  683828924  3777156  781986365  -6557788  267039777  10569886  13031085  14691745  550294  17810549  6928168
2006  1969737146   59708237  734416872  4253528  787218636  -6557842  286253922  10341481  13927432  14568029  507706  26589137  7112762
2007  1998390297   61306315  814751904  4042131  806424753  -6896352  245842714  10711289  14294304  14637213  611793  34449927  6776960
2008  1976173298   42301486  798574077  3195712  806181935  -6238403  246100140  10901875  14872266  14859238  843054  52025898  6879905

Answer 1

fossilArray 似乎没有在 fossilArray[i] += mainArray[i][j]; 行之前初始化。

同样的情况也适用于其他数组。

<小时/>

问题出在这一行:

double fossilArray[29];

C++ 标准不保证局部变量已初始化。 Visual Studio 将未初始化的局部变量设置为某个非零值以帮助定位此问题。