54 lines
871 B
C
54 lines
871 B
C
#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "primes.h"
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#define MAX_NUM 100000000
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#define TRUE 1
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#define FALSE 0
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int main(int argc, char **argv)
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{
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int i, j, match, midpoint;
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long sum = 0;
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char *primes;
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/*
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primes = malloc((MAX_NUM+1)*sizeof(char));
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for (i=1; i<MAX_NUM+1; i++) {
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if (is_prime(i)) {
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primes[i] = TRUE;
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} else {
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primes[i] = FALSE;
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}
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}
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*/
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primes = eratosthenes(MAX_NUM);
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if (primes == NULL) {
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printf("Error");
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return 1;
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}
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for(i=1; i<MAX_NUM; i++) {
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match = TRUE;
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if (!(primes[i+1])) continue;
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midpoint = (int)sqrt(i) + 1;
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for (j=1; j<midpoint; j++) {
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if ((!(i%j)) && (!primes[j+i/j])) {
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match = FALSE;
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break;
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}
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}
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if (match) {
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sum += i;
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}
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}
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printf("The sum of prime-generating numbers less than %d is %ld\n", MAX_NUM, sum);
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free(primes);
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return 0;
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}
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