int main()
{
int input;
int maxnumfactors = 0;
int trinum = 0;
int i, j;
int *primes;
primes = genprimes();
printf("\nPlease input a maximum: \n");
scanf("%d", &input);
// find triangle numbers and store number of divisors until input reached
for(i=1;maxnumfactors<input;i++){
int thisnumfactors;
trinum+=i;
thisnumfactors=findfactors(trinum,primes);
printf("%d %d\n",trinum,thisnumfactors);
if(thisnumfactors>maxnumfactors){
maxnumfactors=thisnumfactors;
}
}
printf("\nMax Factor %d Triangle Number %d\n", maxnumfactors, trinum);
return 0;
}
int main(int argc, const char *argv[]) {
uint64_t total = 0;
unsigned long i;
// Not checking things is cool. JUST BELIEVE IT WILL WORK AND IT WILL.
char *primes = malloc(sizeof(char) * MAXPRIMES);
genprimes(primes);
for (i = 2; i < MAXPRIMES; i++) {
if (primes[i] == TRUE) {
total += i;
}
}
printf("Sum of primes < 2,000,000 = %llu\n", total);
free(primes);
return 0;
}
/*
* Find the longest sequence of primes under 1,000,000
* whose sum is a prime.
*/
void eu050(char *ans) {
const int N = 1000000;
int *primes = malloc(N/2 * sizeof(int));
int n = genprimes(primes, N);
char *sieve = malloc(N);
gensieve(sieve, N);
int *sums = (int *)malloc(n * sizeof(int));
memset(sums, 0, n * sizeof(int));
int t = 0;
for (int i = 0; i < n; i++) {
t += primes[i];
sums[i] = t;
}
int maxlen = 0;
int maxsum = 0;
for (int i = 0; i < n; i++) {
for (int j = i; j < n && sums[j]-sums[i] < N; j++) {
int sum = sums[j] - sums[i];
if (j - i > maxlen && sieve[sum] == 0) {
maxsum = sum;
maxlen = j - i;
}
}
}
sprintf(ans, "%d", maxsum);
free(sums);
free(primes);
free(sieve);
}
