57 lines
1.1 KiB
C
57 lines
1.1 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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int main(int argc, char **argv)
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{
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int a, b, n, p, count, max = 0, save_a, save_b;
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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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for(a = -999; a < 1000; a++)
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{
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for(b = 2; b <= 1000; b++)
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{
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n = 0;
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count = 0;
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while(1)
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{
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p = n * n + a * n + b;
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if(p > 1 && is_prime(p))
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{
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count++;
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n++;
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}
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else
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{
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break;
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}
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}
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if(count > max)
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{
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max = count;
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save_a = a;
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save_b = b;
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}
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}
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}
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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 27\n");
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printf("Answer: %d\n", save_a * save_b);
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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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