即使在我爲包含1000萬條目的數組動態分配空間後,以下代碼在4Gb計算機上運行時也會出現分段錯誤。它可以正常工作,有100萬個條目,即n = 1000000.下面的代碼使用基數排序將整數值及其索引值排序。我應該做些什麼來使這個計劃適用於1000萬條記錄。帶有堆分配的大尺寸陣列上的分段錯誤
int main()
{
int n=10000000; // 10 million entries
int *arr=new int [n]; // declare heap memory for array
int *arri=new int [n]; // declare heap memory for array index
for(int i=0;i<n;i++) // initialize array with random number from 0-100
{
arr[i]=((rand()%100)+0);
}
for(i=0;i<n;i++) // initialize index position for array
{
arri[i]=i;
}
radixsort(arr, n ,arri);
return 0;
}
// The main function to that sorts arr[] of size n using Radix Sort
void radixsort(int *arr, int n,int *arri)
{ int m=99; //getMax(arr,n,arri);
// Find the maximum number to know number of digits
// Do counting sort for every digit. Note that instead
// of passing digit number, exp is passed. exp is 10^i
// where i is current digit number
for (int exp = 1; m/exp > 0; exp *= 10)
countSort(arr, n, exp,arri);
}
void countSort(int *arr, int n, int exp,int *arri)
{
int output[n],output1[n]; // output array
int i, count[10] = {0};
// Store count of occurrences in count[]
for (i = 0; i < n; i++)
{
count[ (arr[i]/exp)%10 ]++;
}
// Change count[i] so that count[i] now contains actual
// position of this digit in output[]
for (i = 1; i < 10; i++)
count[i] += count[i - 1];
// Build the output array
for (i = n - 1; i >= 0; i--)
{
output[count[ (arr[i]/exp)%10 ] - 1] = arr[i];
output1[count[ (arr[i]/exp)%10 ] - 1] = arri[i];
count[ (arr[i]/exp)%10 ]--;
}
// Copy the output array to arr[], so that arr[] now
// contains sorted numbers according to current digit
for (i = 0; i < n; i++)
{
arr[i] = output[i];
arri[i]=output1[i];
}
}
「countSort」中的數組未被動態分配。 – Barmar
請注意,變長數組不是標準的C++。它們在C中,你的編譯器允許它們作爲擴展。 – Barmar