c++ - 段错误错误 11 C++

Question

所以我在代码的开头遇到了段错误。我试过在不同的点运行一些测试，错误似乎是在我为数组分配内存时。我刚刚开始学习堆和堆栈内存，所以我不确定我是否在那里做错了什么。任何帮助将不胜感激。

#include <iostream>
using namespace std;

//Function Prototypes
void sort(int A[], int n);
int findMin(int A[], int n, int j);
int swap(int& a, int& b);
double median(int A[], int n);
void output1(int median);
void output2(double median);

int main()
{
  int size;
  int array[size]; //Segmentaion fault here
  int i = 0;

  cout << "Enter the size of the list (< 1 to quit): ";
  cin >> size;

  while(size >= 1)
    {
      double element;

      cout << "Enter element " << i+1 << ": ";
      cin >> element;

      array[i] = element;

      i++;

      while(i < size)
    {
      cout << "Enter element " << i+1 << ": ";
      cin >> element;

      array[i] = element;
      i++;
    }

      sort(array, size);
      median(array, size);

       cout << "Enter the size of the list (< 1 to quit): ";
       cin >> size;
    } 
  delete [] array;
  return 0;

}


void sort(int A[], int n)
{
  int min;
  for(int i = 0; i < n; i++)
    {
      min = findMin(A,n,i);
      //min = findMinIndex(p, size, i);

      //if(min )
        swap(A[i],A[min]);
      //swap(p[i],p[min]);
    }
}

int findMin(int A[], int n, int j)
{
  int minIndex = j;
  for(int i = j+1; i < n; i++)
    if(A[i]<A[minIndex])
      minIndex = i;
  return minIndex; 
}

int swap(int& a, int& b)
{
  int temp;
  temp = a;
  a = b;
  b = temp;
}

void output1(int median)
{
  cout << "The median is " << median << "." << endl;
}

void output2(double median)
{
  cout << "The median is " << median << "." << endl;
}


double median(int A[], int n)
{


  if(n % 2 == 0)
    {
      int div1 = n / 2;
      int num1 = A[div1];
      int num2 = A[div1 -1];
      double median = (num1 + num2) / 2;
      output2(median);
    }
  else
    {
      int div2 = n - 1;
      int median = div2 / 2;
      output1(median);
    }
}

Answer 1

因为您没有初始化 size，所以该变量中的值实际上可以是任何值。如果它恰好太大，比如 106,840,406，那么您将无法获得该大小的 int[]。

基本上，将您的 size 变量初始化为合理的值。