62 lines
859 B
C++
62 lines
859 B
C++
// C++ version of a Prime Number Finder
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// haplo@mindstab.net
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#include <iostream>
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#include <math.h>
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#include <string>
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#include <stdlib.h>
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using namespace std;
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class CPrimes
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{
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public:
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void countPrimes(unsigned int MAX);
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};
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void CPrimes::countPrimes(unsigned int MAX)
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{
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for(unsigned int cnt = 3; cnt <= MAX; cnt+=2)
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{
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int test = (int)sqrt((double)cnt);
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char isPrime=1;
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for(int i = 3; i<= test; i+=2)
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{
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if(! (cnt % i))
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{
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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)
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{
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cout << cnt << endl;
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}
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}
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}
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int main(int argc, char **argv)
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{
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int MAX;
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if(argc <= 1) {
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cout << "Useage: primescpp [Max Num]" << endl;
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return(1);
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} else {
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MAX = atoi(argv[1]);
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}
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if(MAX < 1) {
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cout << "Invalide Max Num" << endl;
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return(1);
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}
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CPrimes *primes = new CPrimes();
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primes->countPrimes(MAX);
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delete primes;
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return(0);
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}
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