Primes C

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>

#define TRUE 1
#define FALSE 0

int l, n, m, lim;
char* nums;
char input[255];
clock_t start, stop;

int main()
{
    printf("Enter a limit for this search: ");
    gets(input);
    lim = atoi(input);

    start = clock();

    nums = (char *)malloc(lim);

    for (n = 2; n < sqrt(lim); n++)
    {
        if (nums[n] == FALSE)
        {
            m = n * n;
            while (m <= lim)
            {
                nums[m] = TRUE;
                m += n;
            }
        }
    }

    stop = clock();

    printf("It took %f seconds.\n", (double)(stop - start) / 1000);
    system("pause");

    for (n = 2; n < lim; n++)
    {
        if (nums[n] == FALSE)
            printf("%d\n", n);
    }

    free(nums);
    return 0;
}