c++ - 阵列周围的堆栈已损坏

Question

我使用的是 Visual Studios 2015，但遇到了问题。运行时检查失败 #2 - 变量“myArray”周围的堆栈已损坏。我不确定程序中的哪个位置可能会导致我的阵列出现某种损坏。但是当我进行涉及操纵数组的计算时，有几个数字变成了 0.0000 而不是它们原来的样子。有人可以帮忙吗？

#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

int main()
{
   double xmin, xmax;
   const int POINTS = 20;
   const double PI = 3.1416;
   double increments;
   double range, mean;
   double total = 0;
   double myArray[POINTS];
   double number = myArray[0];
   double mode = number;
   int count = 1;
   int countMode = 1;

   cout << "Enter in a value for the minimum x value: ";
   cin >> xmin;
   cout << "Enter in a value for the maximum x value: ";
   cin >> xmax;

   if (xmin < 0)
      increments = (abs(xmin) + xmax) / POINTS;
   else
      increments = (xmax - xmin) / POINTS;

   int i = 0;
   double x = xmin + increments * i;
   double minimum = 0.0572 * cos(4.667 * x) + 0.0218 * PI * cos(12.22 * x);
   double maximum = myArray[19];

   cout << setw(15) << "x |" << setw(15) << "f(x)" << endl;
   cout << setw(32) << setfill('-') << " " << endl;
   cout << setfill(' ');

   for (i = 0; i <= POINTS; i++)
   {
      myArray[i] = 0.0572 * cos(4.667 * x) + 0.0218 * PI * cos(12.22 * x);
      x = xmin + increments * i;
      cout << fixed << showpos << setw(15) << setprecision(2) << x <<  setw(15) << setprecision(4) << myArray[i] << endl;

      if (myArray[i] <= minimum)
         minimum = myArray[i];
      if (myArray[i] > maximum)
         maximum = myArray[i];
   }

   cout << endl;
   range = maximum - minimum;
   for (int count = 0; count <= POINTS; count++)
   {
      total += myArray[count];
   }
   mean = total / POINTS;

   int temp;
   bool swap;
   do
   {
      swap = false;
      for (int i = 0; i < POINTS - 1; i++)
      {
         if (myArray[i] > myArray[i + 1])
         {
            temp = myArray[i];
            myArray[i] = myArray[i + 1];
            myArray[i + 1] = temp;
            swap = true;
       }
      }
   } while (swap);


   for (int i = 0; i <= POINTS; i++)
   {
      if (myArray[i] == number)
      {
         count++;
      }
      else
      {
         if (count > countMode)
         {
            countMode = count;
            mode = number;
         }
         count = 1;
         number = myArray[i];
      }
   }

   cout << "The maximum value is: " << maximum << endl;
   cout << "The minimum value is: " << minimum << endl;
   cout << "The range is: " << range << endl;
   cout << "The mean value is: " << mean << endl;
   cout << "The median value is: " << (myArray[9] + myArray[10]) / 2  <<  endl;
   cout << "The mode value is: " << mode << endl;

   for (i = 0; i <= POINTS; i++)
      cout << myArray[i] << endl;

   system("pause");
   return 0;
}  

Answer 1

double myArray[POINTS];

myArray 是一个包含 20 个 double 的数组 - myArray[0] 到 myArray[19]。

for (i = 0; i <= POINTS; i++)
{
    myArray[i] = 0.0572 * cos(4.667 * x) + 0.0218 * PI * cos(12.22 * x);

这会设置 myArray[0] 到 myArray[20]。不允许访问 myArray[20]，因为它是 20 元素数组的第 21 个元素。

请注意，编译器不会总是很好地为您检测到这个问题。信不信由你，Visual C++ 通过导致程序崩溃来帮您一个忙。