직접 짠 malloc/free 최적화 도와주세요

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
 
#ifdef MJ_ALLOCATOR
#include "mj_allocator.h"
#endif
 
enum {ARRAY_LEN = 50000};
int *array[ARRAY_LEN];
long long sum = 0;
 
int confuse_the_compiler(int n)
{
	return n % 10 > 5 ? -n / 2 : n * 2;
}
 
void start()
{
	for (int i = 1; i <= ARRAY_LEN; ++i)
	{
		for (int j = 0; j < i; ++j)
		{
			array[j] = (int *)malloc(sizeof(int));
			array[j][0] = j + 1;
		}
		for (int j = i - 1; j >= 0; --j)
		{
			sum -= j;
			int n = confuse_the_compiler(array[j][0]);
			if (n != 0)
			{
				sum += n;
				free(array[j]);
			}
		}
	}
}
 
int main()
{
 
#ifdef MJ_ALLOCATOR
	use_mj_allocator(ARRAY_LEN * sizeof(int));
#endif
 
	time_t start_time = clock();
	start();
	time_t end_time = clock();
	printf("\nelapsed time: %.3f\n", (double)(end_time - start_time) / CLOCKS_PER_SEC);
	printf("%lld", sum);
 
#ifdef MJ_ALLOCATOR
	free_mj_allocator();
#endif
 
	return 0;
}

class test
{
	final static int ARRAY_LEN = 50000;
	static int[][] array = new int[ARRAY_LEN][];
	static long sum = 0;
 
	static int confuse_the_compiler(int n)
	{
		return n % 10 > 5 ? -n / 2 : n * 2;
	}
 
	static void start()
	{
		for (int i = 1; i <= ARRAY_LEN; ++i)
		{
			for (int j = 0; j < i; ++j)
			{
				array[j] = new int[1];
				array[j][0] = j + 1;
			}
			for (int j = i - 1; j >= 0; --j)
			{
				sum -= j;
				int n = confuse_the_compiler(array[j][0]);
				if (n != 0)
				{
					sum += n;
					// free(array[j]);
				}
			}
		}
	}
 
	public static void main(String[] args)
	{
		long start_time = System.currentTimeMillis();
		start();
		System.gc();
		long end_time = System.currentTimeMillis();
		System.out.printf("\nelapsed time: %.3f\n", (end_time - start_time) / 1000.0);
		System.out.println(sum);
	}
}