int main()
{
int i = 1;
int last_count = 1;
int new_count;
int count;
while (1) {
if (i%2 == 1)
new_count = count_divisors_half(i+1);
else
new_count = count_divisors(i+1);
count = last_count*new_count;
if (count > DIVISORS)
break;
last_count = new_count;
i++;
}
printf("Result: %d\n", i*(i+1)/2);
return 0;
}
//Brute force!
int main(){
int i=0,divisor_count=0,num=0;
while(count_divisors(num) <= 500){
i++;
num = (i * (i+1))/2;
}
printf("%d\n",num);
return 0;
}
int main(void)
{
long long tnum = 1, topsum = 1;
int nprimes = 0;
int i, j;
int *iscomposite = (int *) calloc(MAX_CHECK+1, sizeof(int));
int *prime_list = (int *) calloc(MAX_CHECK+1, sizeof(int));
for(i = 2; i <= MAX_CHECK; i++)
if(!iscomposite[i]) {
prime_list[nprimes++] = i;
for(j = 2*i; j <= MAX_CHECK; j += i)
iscomposite[j] = 1;
}
while(count_divisors(tnum, prime_list, nprimes) <= 500) {
tnum += ++topsum;
}
printf("With %d divisors, %d is the first triangle number with > 500 divisors.\n", count_divisors(tnum, prime_list, nprimes), tnum);
return 0;
}
int main(void)
{
int next_natural_number = 2;
int current_triangular_number = 1;
int number_of_divisors = 1;
while (number_of_divisors <= 500)
{
current_triangular_number += next_natural_number++;
number_of_divisors = count_divisors(current_triangular_number);
}
printf("next natural number: %d\n", next_natural_number);
printf("trangular number: %d\n", current_triangular_number);
return 0;
}
