38 lines
702 B
C
38 lines
702 B
C
// C version of a Prime Number Finder
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// haplo@mindstab.net
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#include <stdlib.h>
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#include <stdio.h>
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#include <math.h>
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int main(int argc, char ** argv) {
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unsigned int counter, max_test, tester;
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char isPrime;
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unsigned int MAX_NUM;
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if (argc < 2) {
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printf("primesc <MAX NUM>\n");
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return 1;
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} else {
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MAX_NUM = atoi(argv[1]);
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}
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if (MAX_NUM < 1) {
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printf("Invalid MAX_NUM specified\n");
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return 1;
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}
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for (counter =3; counter<= MAX_NUM; counter +=2) {
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max_test = (int) sqrt((double) counter);
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isPrime = 1;
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for (tester =3; tester <= max_test; tester += 2) {
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if(! (counter % tester)) {
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isPrime = 0;
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break;
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}
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}
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if (isPrime) printf("%d\n", counter);
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}
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return 0;
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}
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