25 lines
425 B
C
25 lines
425 B
C
#include <stdio.h>
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#include <math.h>
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#include <assert.h>
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long max(long a, long b) {
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return a > b ? a : b;
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}
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long largest_prime_factor(long n) {
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int p = 2;
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while(n > 1) {
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while(p < n && n%p!=0) p++;
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while(n%p==0) n/=p;
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}
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return p;
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}
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int main( int argc, char *argv[] ) {
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assert(largest_prime_factor(13195) == 29);
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printf("%d\n",largest_prime_factor(600851475143));
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return 0;
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}
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