#include <assert.h>

#include "vararray.h"

struct var_int_array {
    int * data;
    size_t size;
    size_t allocated_size;
};

typedef struct var_int_array varray;

varray * var_int_array_new() { /* O(1) */
    varray * this = malloc(sizeof(varray));
    if (this) {
	this->data = malloc (sizeof(int));
	if (!this->data) {
	    free (this);
	    return 0;
	}
	this->size = 0;
	this->allocated_size = 1;
    }
    return this;
}

int var_int_array_get(const varray * this, size_t idx) { /* O(1) */
    return this->data[idx];
}

void var_int_array_destroy(varray * this) { /* O(1) */
    free (this->data);
    free (this);
}

int var_int_array_append(varray * this, int value) { /* O(1) amortized */
    if (this->size == this->allocated_size) {
	int * p = realloc(this->data, this->allocated_size * 2);
	if (!p)
	    return 0;
	this->data = p;
	this->allocated_size *= 2;
    }
    this->data[this->size] = value;
    this->size += 1;
    return 1;
}