43 lines
814 B
C
43 lines
814 B
C
// C version of a Prime Number Finder
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// Alternate Algorithm: Instead of using sqrt function,
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// track it with two variables
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// haplo@mindstab.net
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#include <stdio.h>
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#include <stdlib.h>
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int main(int argc, char **argv)
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{
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unsigned int i, x, max=2, isP, sqr=4;
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unsigned int MAX_NUM;
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if(argc < 2) {
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printf("primesaltc <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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{
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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(i=3; i<=MAX_NUM; i+=2)
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{
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isP=1;
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for(x = 3; x<=max; x+=2)
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{
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isP = i - (x* (i/x));
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if(isP == 0) break;
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}
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if(isP) printf("%d\n", i,max, sqr);
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if(i>=sqr) {
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max++;
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sqr = max*max -2;
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}
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}
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}
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