How to implement guide with variable-length arrays causing stack overflow in recursive function
I've hit a wall trying to I'm working with a stack overflow scenario when using variable-length arrays (VLAs) within a recursive function in my C program. The function is designed to generate a specific pattern based on the input size, but I noticed that it crashes with larger input values. Here’s a simplified version of my code: ```c #include <stdio.h> #include <stdlib.h> void generatePattern(int size) { if (size <= 0) return; int arr[size]; // Variable-length array for (int i = 0; i < size; i++) { arr[i] = i + 1; } for (int i = 0; i < size; i++) { printf("%d ", arr[i]); } printf("\n"); generatePattern(size - 1); // Recursive call } int main() { int size; printf("Enter size: "); scanf("%d", &size); generatePattern(size); return 0; } ``` When I run this code with an input of around 10000, it results in a stack overflow behavior. I understand that VLAs are allocated on the stack, and it seems like the recursive calls are consuming too much stack space. I've tried switching to dynamic memory allocation using `malloc`, but I end up with memory leaks when I forget to free the memory. Here's my modified attempt using `malloc`: ```c void generatePattern(int size) { if (size <= 0) return; int *arr = malloc(size * sizeof(int)); if (arr == NULL) { fprintf(stderr, "Memory allocation failed\n"); return; } for (int i = 0; i < size; i++) { arr[i] = i + 1; } for (int i = 0; i < size; i++) { printf("%d ", arr[i]); } printf("\n"); generatePattern(size - 1); free(arr); // Free allocated memory } ``` This approach works better, but I’m still concerned about the stack depth due to recursion. Is there a better way to handle this pattern generation without hitting stack overflow, or should I convert the recursion into iteration? What are the best practices for using arrays in recursive functions like this? For reference, this is a production REST API. Am I approaching this the right way? I recently upgraded to C LTS. Has anyone dealt with something similar?