Why double the array size when resizing arrays?
main.c
#include <stdio.h>
#include <stdlib.h>
void add_to_array(int** arr, int* last_index, int* capacity, int elem) {
if (*last_index >= *capacity) {
int* realloc_result = realloc(*arr, sizeof(int) * (*capacity * 2));
printf("We reallocated\n");
if (realloc_result == NULL) {
free(*arr);
printf("Realloc failed for arr\n");
exit(1);
}
*capacity *= 2;
*arr = realloc_result;
}
(*arr)[*last_index] = elem;
(*last_index)++;
}
int main(int argc, char *argv[]) {
int capacity = 16;
int* arr = malloc(sizeof(int) * capacity);
int last_index = 0;
add_to_array(&arr, &last_index, &capacity, 17);
add_to_array(&arr, &last_index, &capacity, 18);
add_to_array(&arr, &last_index, &capacity, 19);
add_to_array(&arr, &last_index, &capacity, 20);
add_to_array(&arr, &last_index, &capacity, 21);
add_to_array(&arr, &last_index, &capacity, 22);
add_to_array(&arr, &last_index, &capacity, 23);
add_to_array(&arr, &last_index, &capacity, 24);
add_to_array(&arr, &last_index, &capacity, 25);
add_to_array(&arr, &last_index, &capacity, 26);
add_to_array(&arr, &last_index, &capacity, 27);
add_to_array(&arr, &last_index, &capacity, 28);
add_to_array(&arr, &last_index, &capacity, 29);
add_to_array(&arr, &last_index, &capacity, 30);
add_to_array(&arr, &last_index, &capacity, 31);
add_to_array(&arr, &last_index, &capacity, 32);
add_to_array(&arr, &last_index, &capacity, 33);
add_to_array(&arr, &last_index, &capacity, 34);
add_to_array(&arr, &last_index, &capacity, 35);
add_to_array(&arr, &last_index, &capacity, 36);
add_to_array(&arr, &last_index, &capacity, 37);
add_to_array(&arr, &last_index, &capacity, 38);
add_to_array(&arr, &last_index, &capacity, 39);
add_to_array(&arr, &last_index, &capacity, 40);
add_to_array(&arr, &last_index, &capacity, 41);
add_to_array(&arr, &last_index, &capacity, 42);
add_to_array(&arr, &last_index, &capacity, 43);
add_to_array(&arr, &last_index, &capacity, 44);
add_to_array(&arr, &last_index, &capacity, 45);
add_to_array(&arr, &last_index, &capacity, 46);
add_to_array(&arr, &last_index, &capacity, 47);
add_to_array(&arr, &last_index, &capacity, 48);
add_to_array(&arr, &last_index, &capacity, 49);
add_to_array(&arr, &last_index, &capacity, 50);
add_to_array(&arr, &last_index, &capacity, 51);
printf("Capacity: %d\n", capacity);
printf("Last Index: %d\n", last_index);
printf("First element: %d\n", arr[0]);
printf("Last element: %d\n", arr[last_index - 1]);
free(arr);
return 0;
}
