#include <stdio.h>
#include <stdlib.h>
int* allocate_array(int size) {
int *arr = (int *) malloc(size * sizeof(int));
if (arr == NULL) {
printf("malloc error\n");
exit(1);
}
return arr;
}
int* resize_array(int *arr, int old_size, int new_size) {
int *tmp = (int *) realloc(arr, new_size * sizeof(int));
if (tmp == NULL) {
free(arr);
printf("realloc error\n");
exit(1);
}
// Optionally initialize new elements to 0
for (int i = old_size; i < new_size; i++) {
tmp[i] = 0;
}
return tmp;
}
void print_array(int *arr, int size) {
for (int i = 0; i < size; i++) {
printf("%i\n", arr[i]);
}
}
int main(void) {
int *arr = allocate_array(3);
arr[0] = 10;
arr[1] = 20;
arr[2] = 30;
print_array(arr, 3);
arr = resize_array(arr, 3, 5);
printf("\nafter realloc\n");
print_array(arr, 5);
arr[3] = 40;
arr[4] = 50;
printf("\nafter realloc & set new data\n");
print_array(arr, 5);
free(arr);
return 0;
}
/*
run
10
20
30
after realloc
10
20
30
0
0
after realloc & set new data
10
20
30
40
50
*/
