57 lines
1.0 KiB
C
57 lines
1.0 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <math.h>
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#include <time.h>
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#include "projecteuler.h"
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#define N 1000000
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int main(int argc, char **argv)
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{
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int i, j, max = 0, max_p = 0, sum, count;
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int *primes;
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double elapsed;
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struct timespec start, end;
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clock_gettime(CLOCK_MONOTONIC, &start);
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primes = sieve(N);
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for(i = 2; i < N; i++)
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{
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if(primes[i])
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{
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count = 1;
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sum = i;
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for(j = i + 1; j < N && sum < N; j++)
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{
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if(primes[j])
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{
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sum += j;
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count++;
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if(sum < N && primes[sum] && count > max)
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{
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max = count;
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max_p = sum;
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}
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}
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}
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}
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}
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free(primes);
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clock_gettime(CLOCK_MONOTONIC, &end);
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elapsed = (end.tv_sec - start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
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printf("Project Euler, Problem 50\n");
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printf("Answer: %d\n", max_p);
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printf("Elapsed time: %.9lf seconds\n", elapsed);
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return 0;
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}
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