C++錯誤消息免費（）：無效下一個大小（快）

Question

我第一次使用動態數組。我喜歡使用它們的原因是我想創建可變大小的數組。

在運行該程序時，我在函數「assign_noise_levels ...」後收到以下錯誤消息。所以程序的最後一個輸出是「完成噪聲水平！」。

*** Error in `./test_linear_instance': free(): invalid next size (fast): 0x0000000000e78010 *** 
======= Backtrace: ========= 
/lib64/libc.so.6[0x3803075acf] 
/lib64/libc.so.6[0x380307cdf8] 
./test_linear_instance[0x40150c] 
/lib64/libc.so.6(__libc_start_main+0xf5)[0x3803021d65] 
./test_linear_instance[0x400db9] 
======= Memory map: ======== 
00400000-00403000 r-xp 00000000 00:2b 1525818       /ufs/hommerso/SCIP/test_linear_instance 
00602000-00603000 r--p 00002000 00:2b 1525818       /ufs/hommerso/SCIP/test_linear_instance 
00603000-00604000 rw-p 00003000 00:2b 1525818       /ufs/hommerso/SCIP/test_linear_instance 
00e78000-00e99000 rw-p 00000000 00:00 0         [heap] 
3802c00000-3802c20000 r-xp 00000000 08:02 1967211      /usr/lib64/ld-2.18.so 
3802e1f000-3802e20000 r--p 0001f000 08:02 1967211      /usr/lib64/ld-2.18.so 
3802e20000-3802e21000 rw-p 00020000 08:02 1967211      /usr/lib64/ld-2.18.so 
3802e21000-3802e22000 rw-p 00000000 00:00 0 
3803000000-38031b4000 r-xp 00000000 08:02 1967262      /usr/lib64/libc-2.18.so 
38031b4000-38033b3000 ---p 001b4000 08:02 1967262      /usr/lib64/libc-2.18.so 
38033b3000-38033b7000 r--p 001b3000 08:02 1967262      /usr/lib64/libc-2.18.so 
38033b7000-38033b9000 rw-p 001b7000 08:02 1967262      /usr/lib64/libc-2.18.so 
38033b9000-38033be000 rw-p 00000000 00:00 0 
3803400000-3803505000 r-xp 00000000 08:02 198/usr/lib64/libm-2.18.so 
3803505000-3803705000 ---p 00105000 08:02 198/usr/lib64/libm-2.18.so 
3803705000-3803706000 r--p 00105000 08:02 198/usr/lib64/libm-2.18.so 
3803706000-3803707000 rw-p 00106000 08:02 198/usr/lib64/libm-2.18.so 
3804400000-3804415000 r-xp 00000000 08:02 1983836      /usr/lib64/libgcc_s-4.8.3-20140624.so.1 
3804415000-3804614000 ---p 00015000 08:02 1983836      /usr/lib64/libgcc_s-4.8.3-20140624.so.1 
3804614000-3804615000 r--p 00014000 08:02 1983836      /usr/lib64/libgcc_s-4.8.3-20140624.so.1 
3804615000-3804616000 rw-p 00015000 08:02 1983836      /usr/lib64/libgcc_s-4.8.3-20140624.so.1 
3807c00000-3807cea000 r-xp 00000000 08:02 1983837      /usr/lib64/libstdc++.so.6.0.19 
3807cea000-3807ee9000 ---p 000ea000 08:02 1983837      /usr/lib64/libstdc++.so.6.0.19 
3807ee9000-3807ef1000 r--p 000e9000 08:02 1983837      /usr/lib64/libstdc++.so.6.0.19 
3807ef1000-3807ef3000 rw-p 000f1000 08:02 1983837      /usr/lib64/libstdc++.so.6.0.19 
3807ef3000-3807f08000 rw-p 00000000 00:00 0 
7feca8220000-7feca8225000 rw-p 00000000 00:00 0 
7feca825c000-7feca8260000 rw-p 00000000 00:00 0 
7fffbb4d4000-7fffbb4f5000 rw-p 00000000 00:00 0       [stack] 
7fffbb5c7000-7fffbb5c9000 r-xp 00000000 00:00 0       [vdso] 
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0     [vsyscall] 
Aborted 

這裏是我的代碼：

/* CREATE .dat FILE WITH LINEAR NOISE_FUNCTION  */ 


# include <iostream> 
# include <fstream> 
# include <random> 
# include <cmath> 

using namespace std ; 

typedef double* DoublePtr ; 
typedef int* IntPtr ; 



void make_grid(int& width, int& height, int& length, int& steps) 
{ 
    do 
    { 
     cout << "Enter an even number for the width of the grid (km): " ; 
     cin >> width ; 
    } while (width % 2 == 1 || width <= 0) ; 
    do 
    { 
     cout << "Enter an even number for the height of the grid (km): " ; 
     cin >> height ; 
    } while (height % 2 == 1 || height <= 0) ; 

    do 
    { 
     cout << "Enter an even number for the length of the runway (km): " ; 
     cin >> length ; 
    } while (length > width || length <=0) ; 
    do 
    { 
     cout << "Enter the number of measure points per km: " ; 
     cin >> steps ; 
    } while (steps <= 0) ; 
} 


void assign_noise_levels_to_aircrafts(int& nr_of_aircrafts, double& max_noise_level, double& min_noise_level, DoublePtr noise_level) 
{ 
    do 
    { 
     cout << endl << "Enter number of aircraft types: " ; 
     cin >> nr_of_aircrafts ;  
    } while (nr_of_aircrafts <= 0) ; 
    do 
    { 
     cout << "Enter the maximum noise level: " ; 
     cin >> max_noise_level ; 
    } while (max_noise_level < 0) ; 
    if(nr_of_aircrafts == 1) 
    { 
     noise_level[0] = max_noise_level ; 
     cout << endl << "There is only one aircraft. Its noise level is " << noise_level[0] << endl ; 
    } 
    else 
    { 
     do 
     { 
      cout << "Enter the minimum noise level: " ; 
      cin >> min_noise_level ; 
     } while (min_noise_level > max_noise_level || min_noise_level < 0) ; 
     cout << endl ;  
     for(int i=0 ; i < nr_of_aircrafts ; i++)   
     { 
      noise_level[i] = max_noise_level + i * (min_noise_level - max_noise_level)/(nr_of_aircrafts - 1) ; 
      cout << "The noise level of aircraft " << i+1 << " is " << noise_level[i] << endl ; 
     } 
    } 
} 


double dist(int point_1[2], int point_2[2]) 
{ 
    double d_0 = point_1[0]-point_2[0] ; 
    double d_1 = point_1[1]-point_2[1] ; 
    double sum = d_0*d_0 + d_1*d_1 ; 
    double distance = sqrt(sum) ; 

return distance ; 
} 


void put_houses(int grid_height, int grid_width, IntPtr *nr_of_houses) 
{ 
    random_device rd ; 
    mt19937 generator(rd()) ; 
    uniform_int_distribution<int> uni(0,1) ; 

    cout << endl << "The houses are located as follows:" << endl ; 
    for(int i=0 ; i<grid_height ; i++)   
    { for(int j=0 ; j<grid_width ; j++) 
     { nr_of_houses[i][j] = uni(generator) ; 
      cout << nr_of_houses[i][j] << " " ; 
     } 
     cout << endl ; 
    } 
    cout << endl ; 
} 




int main() 
{ 

// designing the grid 
    int steps ;       
    int width ;       
    int height ;        
    int length ;        

    make_grid(width, height, length, steps) ; 

// defining aircrafts by calculating their noise levels 
    int nr_of_aircrafts ; 
    double max_noise_level ; 
    double min_noise_level ; 
    DoublePtr noise_level ; 
    noise_level = new double[nr_of_aircrafts] ;   

    assign_noise_levels_to_aircrafts(nr_of_aircrafts, max_noise_level, min_noise_level, noise_level) ; 
    cout << "Done with noise levels!" << endl ; 

// calculating noise pollution for every aircraft 
    int grid_width = (width*steps) + 1 ;     
    int grid_height = (height*steps) + 1 ;    

    int grid_mid_width = (1/2)*width*steps ; 
    int grid_mid_height = (1/2)*height*steps ;   
    int runway_ending_1 = grid_mid_width - (1/2)*length*steps ; 
    int runway_ending_2 = grid_mid_width + (1/2)*length*steps ; 

    // ... ... 

delete[] noise_level ; 


// putting one house on the grid points at random 
    IntPtr *nr_of_houses = new IntPtr[grid_height] ; 
    for (int i=0 ; i<grid_height ; i++) 
     nr_of_houses[i] = new int[grid_width] ;   

    put_houses(grid_height, grid_width, nr_of_houses) ; 
    cout << "Done with put_houses!" << endl; 

for(int i=0 ; i<grid_height ; i++) 
    delete[] nr_of_houses[i] ; 
delete[] nr_of_houses ; 

// test if the whole program is run 
    cout << "Done!" << endl ; 

return 0 ; 
} 

一定是某種錯誤使用這些動態數組的內存中去，但我不知道到底什麼是錯的。程序的先前運行在功能put_houses之後立即顯示此錯誤消息，但現在消息正在更早出現。

任何人都可以請解釋我做錯了什麼，我應該如何解決這個問題？

Answer 1

立即解決問題的是，在這一點上：

noise_level = new double[nr_of_aircrafts]; 

你沒有給nr_of_aircrafts值。只有在致電assign_noise_levels_to_aircrafts時纔會給予價值。

更常見的問題是，您正在使用指針和new，而不是讓std::vector等自動管理您的所有陣列。如果你繼續這樣做，你可以期待更多模糊的內存管理問題和長時間的調試會話。