Add more solutions

Added solutions for problems from 41 to 5, both in C and python
This commit is contained in:
daniele 2019-09-22 17:47:09 +02:00
parent 7bab173c05
commit f8cce530b5
Signed by: fuxino
GPG Key ID: 6FE25B4A3EE16FDA
22 changed files with 1105 additions and 0 deletions

48
C/p041.c Normal file

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "projecteuler.h"
int count_digits(int n);
int main(int argc, char **argv)
{
int i, found = 0;
double elapsed;
struct timespec start, end;
clock_gettime(CLOCK_MONOTONIC, &start);
for(i = 7654321; !found && i > 0; i -= 2)
{
if(is_pandigital(i, count_digits(i)) && is_prime(i))
{
printf("Project Euler, Problem 41\n");
printf("Answer: %d\n", i);
found = 1;
}
}
clock_gettime(CLOCK_MONOTONIC, &end);
elapsed = (end.tv_sec - start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
printf("Elapsed time: %.9lf seconds\n", elapsed);
return 0;
}
int count_digits(int n)
{
int i = 0;
while(n > 0)
{
i++;
n /= 10;
}
return i;
}

96
C/p042.c Normal file

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
int is_triang(int n);
int main(int argc, char **argv)
{
int i, j, n, len, value, count = 0;
char *line, **words;
double elapsed;
FILE *fp;
struct timespec start, end;
clock_gettime(CLOCK_MONOTONIC, &start);
if((fp = fopen("words.txt", "r")) == NULL)
{
fprintf(stderr, "Error while opening file %s\n", "words.txt");
return 1;
}
fscanf(fp, "%ms", &line);
fclose(fp);
n = 1;
len = strlen(line);
for(i = 0; i < len; i++)
{
if(line[i] == ',')
{
n++;
}
}
if((words = (char **)malloc(n*sizeof(char *))) == NULL)
{
fprintf(stderr, "Error while allocating memory\n");
return 1;
}
words[0] = strtok(line, ",\"");
for(i = 1; i < n; i++)
{
words[i] = strtok(NULL, ",\"");
}
for(i = 0; i < n; i++)
{
value = 0;
len = strlen(words[i]);
for(j = 0; j < len; j++)
{
value += (words[i][j] - 'A' + 1);
}
if(is_triang(value))
{
count++;
}
}
free(line);
free(words);
clock_gettime(CLOCK_MONOTONIC, &end);
elapsed = (end.tv_sec-start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
printf("Project Euler, Problem 42\n");
printf("Answer: %d\n", count);
printf("Elapsed time: %.9lf seconds\n", elapsed);
return 0;
}
int is_triang(int n)
{
int i, j;
for(i = 1, j = 1; j <= n; i++, j += i)
{
if(n == j)
{
return 1;
}
}
return 0;
}

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C/p043.c Normal file

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#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void permute(int *v, int i, int n);
void swap(int *a, int *b);
int has_property(int *v);
long int sum = 0;
int main(int argc, char **argv)
{
int n[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
double elapsed;
struct timespec start, end;
clock_gettime(CLOCK_MONOTONIC, &start);
permute(n, 0, 9);
clock_gettime(CLOCK_MONOTONIC, &end);
elapsed = (end.tv_sec - start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
printf("Project Euler, Problem 43\n");
printf("Answer: %ld\n", sum);
printf("Elapsed time: %.9lf seconds\n", elapsed);
return 0;
}
void permute(int *v, int i, int n)
{
int j;
if(i == n)
{
if(has_property(v))
{
sum += v[0] * 1e9 + v[1] * 1e8 + v[2] * 1e7 + v[3] * 1e6 + v[4] * 1e5 + v[5] * 1e4 + v[6] * 1e3 + v[7] * 1e2 + v[8] * 1e1 + v[9];
}
}
else
{
for(j = i; j <= n; j++)
{
swap((v+i), (v+j));
permute(v, i+1, n);
swap((v+i), (v+j));
}
}
}
void swap(int *a, int *b)
{
int tmp;
tmp = *a;
*a = *b;
*b = tmp;
}
int has_property(int *v)
{
long int value;
value = v[1] * 100 + v[2] * 10 + v[3];
if(value % 2 != 0)
{
return 0;
}
value = v[2] * 100 + v[3] * 10 + v[4];
if(value % 3 != 0)
{
return 0;
}
value = v[3] * 100 + v[4] * 10 + v[5];
if(value % 5 != 0)
{
return 0;
}
value = v[4] * 100 + v[5] * 10 + v[6];
if(value % 7 != 0)
{
return 0;
}
value = v[5] * 100 + v[6] * 10 + v[7];
if(value % 11 != 0)
{
return 0;
}
value = v[6] * 100 + v[7] * 10 + v[8];
if(value %13 != 0)
{
return 0;
}
value = v[7] * 100 + v[8] * 10 + v[9];
if(value % 17 != 0)
{
return 0;
}
return 1;
}

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C/p044.c Normal file

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "projecteuler.h"
int main(int argc, char **argv)
{
int n, m, pn, pm, found = 0;
double elapsed;
struct timespec start, end;
clock_gettime(CLOCK_MONOTONIC, &start);
n = 2;
while(!found)
{
pn = n * (3 * n - 1) / 2;
for(m = 1; m < n; m++)
{
pm = m * (3 * m - 1) / 2;
if(is_pentagonal(pn+pm) && is_pentagonal(pn-pm))
{
found = 1;
break;
}
}
n++;
}
clock_gettime(CLOCK_MONOTONIC, &end);
elapsed = (end.tv_sec - start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
printf("Project Euler, Problem 44\n");
printf("Answer: %d\n", pn-pm);
printf("Elapsed time: %.9lf seconds\n", elapsed);
return 0;
}

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C/p045.c Normal file

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "projecteuler.h"
int main(int argc, char **argv)
{
int found = 0;
long int i, n;
double elapsed;
struct timespec start, end;
clock_gettime(CLOCK_MONOTONIC, &start);
i = 143;
while(!found)
{
i++;
n = i * (2 * i - 1);
if(is_pentagonal(n))
{
found = 1;
}
}
clock_gettime(CLOCK_MONOTONIC, &end);
elapsed = (end.tv_sec - start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
printf("Project Euler, Problem 45\n");
printf("Answer: %ld\n", n);
printf("Elapsed time: %.9lf seconds\n", elapsed);
return 0;
}

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C/p046.c Normal file

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "projecteuler.h"
#define N 10000
int goldbach(int n);
int *primes;
int main(int argc, char **argv)
{
int i, found = 0;
double elapsed;
struct timespec start, end;
clock_gettime(CLOCK_MONOTONIC, &start);
primes = sieve(N);
for(i = 3; !found && i < N; i += 2)
{
if(!primes[i])
{
if(!goldbach(i))
{
found = 1;
}
}
}
free(primes);
clock_gettime(CLOCK_MONOTONIC, &end);
elapsed = (end.tv_sec - start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
printf("Project Euler, Problem 46\n");
printf("Answer: %d\n", i-2);
printf("Elapsed time: %.9lf seconds\n", elapsed);
return 0;
}
int goldbach(int n)
{
int i, j, tmp;
for(i = 2; i < n; i++)
{
if(primes[i])
{
j = 1;
do
{
tmp = i + 2 * j * j;
if(tmp == n)
{
return 1;
}
j++;
}while(tmp < n);
}
}
return 0;
}

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C/p047.c Normal file

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "projecteuler.h"
#define N 150000
int count_distinct_factors(int n);
int *primes;
int main(int argc, char **argv)
{
int i, found = 0;
double elapsed;
struct timespec start, end;
clock_gettime(CLOCK_MONOTONIC, &start);
primes = sieve(N);
for(i = 645; !found && i < N - 3; i++)
{
if(!primes[i] && !primes[i+1] && !primes[i+2] && !primes[i+3])
{
if(count_distinct_factors(i) == 4 && count_distinct_factors(i+1) == 4 &&
count_distinct_factors(i+2) == 4 && count_distinct_factors(i+3) == 4)
{
found = 1;
}
}
}
free(primes);
clock_gettime(CLOCK_MONOTONIC, &end);
elapsed = (end.tv_sec - start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
printf("Project Euler, Problem 47\n");
printf("Answer: %d\n", i-1);
printf("Elapsed time: %.9lf seconds\n", elapsed);
return 0;
}
int count_distinct_factors(int n)
{
int i, count=0;
if(n % 2 == 0)
{
count++;
do
{
n /= 2;
}while(n % 2 == 0);
}
for(i = 3; n > 1; i += 2)
{
if(primes[i] && n % i == 0)
{
count++;
do
{
n /= i;
}while(n % i == 0);
}
}
return count;
}

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C/p048.c Normal file

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <gmp.h>
int main(int argc, char **argv)
{
int i;
double elapsed;
struct timespec start, end;
mpz_t power, sum;
char *res;
clock_gettime(CLOCK_MONOTONIC, &start);
mpz_init_set_ui(sum, 0);
mpz_init(power);
for(i = 1; i <= 1000; i++)
{
mpz_ui_pow_ui(power, i, i);
mpz_add(sum, sum, power);
}
res = mpz_get_str(NULL, 10, sum);
mpz_clears(power, sum, NULL);
clock_gettime(CLOCK_MONOTONIC, &end);
elapsed = (end.tv_sec - start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
printf("Project Euler, Problem 48\n");
printf("Answer: %s\n", res+strlen(res)-10);
printf("Elapsed time: %.9lf seconds\n", elapsed);
return 0;
}

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "projecteuler.h"
#define N 10000
int check_digits(int a, int b);
int *primes;
int main(int argc, char **argv)
{
int i, j, found = 0;
double elapsed;
struct timespec start, end;
clock_gettime(CLOCK_MONOTONIC, &start);
primes = sieve(N);
for(i = 1489; i < N && !found; i++)
{
if(primes[i])
{
for(j = 1; j < 4255; j++)
{
if(i + 2 * j < N && primes[i+j] && primes[i+2*j] &&
check_digits(i, i+j) && check_digits(i, i+2*j))
{
found = 1;
break;
}
}
}
}
free(primes);
clock_gettime(CLOCK_MONOTONIC, &end);
elapsed = (end.tv_sec - start.tv_sec) + (double)(end.tv_nsec - start.tv_nsec) / 1000000000;
printf("Project Euler, Problem 49\n");
printf("Answer: %d%d%d\n", i-1, i-1+j, i-1+2*j);
printf("Elapsed time: %.9lf seconds\n", elapsed);
return 0;
}
int check_digits(int a, int b)
{
int i;
int digits1[10] = {0}, digits2[10] = {0};
while(a > 0)
{
digits1[a%10]++;
a /= 10;
}
while(b > 0)
{
digits2[b%10]++;
b /= 10;
}
for(i = 0; i < 10; i++)
{
if(digits1[i] != digits2[i])
{
return 0;
}
}
return 1;
}

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

1
C/words.txt Normal file

File diff suppressed because one or more lines are too long

29
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#!/usr/bin/python3
from timeit import default_timer
from projecteuler import is_pandigital, is_prime
def count_digits(n):
i = 0
while n > 0:
i = i + 1
n = n // 10
return i
def main():
start = default_timer()
for i in range(7654321, 0, -2):
if is_pandigital(i, count_digits(i)) and is_prime(i):
print('Project Euler, Problem 41')
print('Answer: {}'.format(i))
break
end = default_timer()
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

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#!/usr/bin/python3
from timeit import default_timer
def is_triang(n):
i = 1
j = 1
while j <= n:
if n == j:
return True
i = i + 1
j = j + i
return False
def main():
start = default_timer()
try:
fp = open('words.txt', 'r')
except:
print('Error while opening file {}'.format('words.txt'))
exit(1)
words = list(fp.readline().replace('"', '').split(','))
fp.close()
count = 0
for word in words:
value = 0
l = len(word)
for j in range(l):
value = value + ord(word[j]) - ord('A') + 1
if is_triang(value):
count = count + 1
end = default_timer()
print('Project Euler, Problem 42')
print('Answer: {}'.format(count))
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

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#!/usr/bin/python3
from itertools import permutations
from timeit import default_timer
def has_property(n):
value = int(n[1]) * 100 + int(n[2]) * 10 + int(n[3])
if value % 2 != 0:
return False
value = int(n[2]) * 100 + int(n[3]) * 10 + int(n[4])
if value % 3 != 0:
return False
value = int(n[3]) * 100 + int(n[4]) * 10 + int(n[5])
if value % 5 != 0:
return False
value = int(n[4]) * 100 + int(n[5]) * 10 + int(n[6])
if value % 7 != 0:
return False
value = int(n[5]) * 100 + int(n[6]) * 10 + int(n[7])
if value % 11 != 0:
return False
value = int(n[6]) * 100 + int(n[7]) * 10 + int(n[8])
if value % 13 != 0:
return False
value = int(n[7]) * 100 + int(n[8]) * 10 + int(n[9])
if value % 17 != 0:
return False
return True
def main():
start = default_timer()
perm = list(permutations('0123456789'))
sum_ = 0
for i in perm:
if has_property(i):
sum_ = sum_ + int(''.join(map(str, i)))
end = default_timer()
print('Project Euler, Problem 43')
print('Answer: {}'.format(sum_))
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

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#!/usr/bin/python3
from math import sqrt
from timeit import default_timer
from projecteuler import is_pentagonal
def main():
start = default_timer()
found = 0
n = 2
while not found:
pn = n * (3 * n - 1) // 2
for m in range(1, n):
pm = m * (3 * m - 1) // 2
if is_pentagonal(pn+pm) and is_pentagonal(pn-pm):
found = 1
break
n = n + 1
end = default_timer()
print('Project Euler, Problem 44')
print('Answer: {}'.format(pn-pm))
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

29
Python/p045.py Normal file

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#!/usr/bin/python3
from math import sqrt
from timeit import default_timer
from projecteuler import is_pentagonal
def main():
start = default_timer()
found = 0
i = 143
while not found:
i = i + 1
n = i * (2 * i - 1)
if is_pentagonal(n):
found = 1
end = default_timer()
print('Project Euler, Problem 45')
print('Answer: {}'.format(n))
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

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#!/usr/bin/python3
from timeit import default_timer
from projecteuler import sieve
def goldbach(n):
global primes
for i in range(2, n):
if primes[i] == 1:
j = 1
while True:
tmp = i + 2 * j * j
if tmp == n:
return True
j = j + 1
if tmp >= n:
break
return False
def main():
start = default_timer()
global primes
N = 10000
primes = sieve(N)
found = 0
i = 3
while not found and i < N:
if primes[i] == 0:
if not goldbach(i):
found = 1
i = i + 2
end = default_timer()
print('Project Euler, Problem 46')
print('Answer: {}'.format(i-2))
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

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#!/usr/bin/python3
from timeit import default_timer
from projecteuler import sieve
def count_distinct_factors(n):
global primes
count = 0
if n % 2 == 0:
count = count + 1
while True:
n = n // 2
if n % 2 != 0:
break
i = 3
while n > 1:
if primes[i] == 1 and n % i == 0:
count = count + 1
while True:
n = n // i
if n % i != 0:
break
i = i + 2
return count
def main():
start = default_timer()
global primes
N = 150000
primes = sieve(N)
found = 0
i = 645
while not found and i < N - 3:
if primes[i] == 0 and primes[i+1] == 0 and primes[i+2] == 0 and primes[i+3] == 0:
if count_distinct_factors(i) == 4 and count_distinct_factors(i+1) == 4 and count_distinct_factors(i+2) == 4 and count_distinct_factors(i+3) == 4:
found = 1
i = i + 1
end = default_timer()
print('Project Euler, Problem 47')
print('Answer: {}'.format(i-1))
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

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#!/usr/bin/python3
from timeit import default_timer
def main():
start = default_timer()
sum_ = 0
for i in range(1, 1001):
power = i ** i
sum_ = sum_ + power
end = default_timer()
print('Project Euler, Problem 48')
print('Answer: {}'.format(str(sum_)[-10:]))
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

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#!/usr/bin/python3
from numpy import zeros
from timeit import default_timer
from projecteuler import sieve
def check_digits(a, b):
digits1 = zeros(10, int)
digits2 = zeros(10, int)
while a > 0:
digits1[a%10] = digits1[a%10] + 1
a = a // 10
while b > 0:
digits2[b%10] = digits2[b%10] + 1
b = b // 10
for i in range(10):
if digits1[i] != digits2[i]:
return False
return True
def main():
start = default_timer()
N = 10000
primes = sieve(N)
found = 0
i = 1489
while i < N and found == 0:
if primes[i] == 1:
for j in range(1, 4255):
if i + 2 * j < N and primes[i+j] == 1 and primes[i+2*j] == 1 and\
check_digits(i, i+j) and check_digits(i, i+2*j):
found = 1
break
i = i + 1
end = default_timer()
print('Project Euler, Problem 49')
print('Answer: {}'.format(str(i-1)+str(i-1+j)+str(i-1+2*j)))
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

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#!/usr/bin/python3
from timeit import default_timer
from projecteuler import sieve
def main():
start = default_timer()
N = 1000000
primes = sieve(N)
max_ = 0
max_p = 0
for i in range(2, N):
if primes[i] == 1:
count = 1
sum_ = i
j = i + 1
while j < N and sum_ < N:
if primes[j] == 1:
sum_ = sum_ + j
count = count + 1
if sum_ < N and primes[sum_] == 1 and count > max_:
max_ = count
max_p = sum_
j = j + 1
end = default_timer()
print('Project Euler, Problem 50')
print('Answer: {}'.format(max_p))
print('Elapsed time: {:.9f} seconds'.format(end - start))
if __name__ == '__main__':
main()

1
Python/words.txt Normal file

File diff suppressed because one or more lines are too long