TheAlgorithms-C/project_euler/problem_7/sol.c

41 lines
767 B
C

/**
* \file
* \brief [Problem 7](https://projecteuler.net/problem=7) solution.
* @see Another version: problem_7/sol2.c
*/
#include <stdio.h>
#include <stdlib.h>
/** Main function
* @return 0 on exit
*/
int main(void)
{
char *sieve;
size_t i;
unsigned count = 0;
size_t n = 1000000;
const unsigned target = 10001;
sieve = (char *)calloc(n, sizeof(char));
for (i = 2; i < n; i++)
{
if (!sieve[i])
{
size_t j;
count++;
if (count == target)
{
printf("%lu\n", i);
break;
}
for (j = i * 2; j < n; j += i)
{
sieve[j] = 1;
}
}
}
free(sieve);
return 0;
}