Esempio n. 1
0
# Problem link: http://projecteuler.net/index.php?section=problems&id=35

# use dictionary and prime generator
from myMath import genPrime

def getDigits(n):
    L = []
    while n != 0:
        L.append(n % 10)
        n /= 10
    return L

n = 1000000
L = genPrime(n);
D = {}
for prime in L:
    D[prime] = True
res = 0
for prime in L:
    ok = True
    digits = getDigits(prime)
    num = len(digits)
    for i in range(0, num):
        value = 0
        for j in range(i, i - num, -1):
            value = value * 10 + digits[j]
        if not D.has_key(value):
            ok = False
            break
    if ok:
        res += 1
Esempio n. 2
0
# Problem link: http://projecteuler.net/index.php?section=problems&id=50

from myMath import genPrime

n = 1000000
primeList = genPrime(n)
D = {}
for prime in primeList:
    D[prime] = True
num = len(primeList)
summ = [0] * num
for i in range(0, num):
    summ[i] = primeList[i]
    if i != 0:
        summ[i] += summ[i - 1]
resCnt = 0
resValue = 0
for i in range(0, num - resCnt):
    if primeList[i] * resCnt > n:
        break
    for j in range(i + resCnt, num):
        if i == 0:
            value = summ[j]
        else:
            value = summ[j] - summ[i - 1]
        if value >= n:
            break
        cnt = j - i + 1
        if D.has_key(value) and cnt > resCnt:
            resCnt = cnt
            resValue = value
Esempio n. 3
0
# Problem link: http://projecteuler.net/index.php?section=problems&id=10

from myMath import genPrime

primes = genPrime(2000000)
summ = 0
for k in primes:
    summ += k
print summ

Esempio n. 4
0
        if isPrime(num):
            return num
        else:
            return 0
    for k in range(n, 0, -1):
        if not used[k]:
            digits[kth] = k
            used[k] = True
            res = dfs(kth + 1, n, used, digits)
            if res != 0:
                return res
            used[k] = False
    return 0

def findPandigitalPrime(n):
    used = [False] * (n + 1)
    digits = [0] * n
    return dfs(0, n, used, digits)

m = 40000
primes = genPrime(m)
n = 9
res = 0
while True:
    res = findPandigitalPrime(n)
    if res != 0:
        break
    n -= 1
print res

Esempio n. 5
0
# Problem link: http://projecteuler.net/index.php?section=problems&id=37

from myMath import genPrime

n = 1000000
primes = genPrime(n)
D = {}
for prime in primes:
    D[prime] = True
res = 0
for prime in primes:
    if prime < 10:
        continue
    ok = True
    mod = 10
    while True:
        if mod > prime:
            break
        if not D.has_key(prime % mod) or not D.has_key(prime / mod):
            ok = False
            break
        mod *= 10
    if ok:
        res += prime
print res

Esempio n. 6
0
# Problem link: http://projecteuler.net/index.php?section=problems&id=12

from myMath import genPrime

prime = genPrime(10000)

def divisorNumber(n):
    res = 1
    for p in prime:
        if p * p > n:
            break
        k = 0
        while n % p == 0:
            k = k + 1
            n = n / p
        res = res * (k + 1)
    if n != 1:
        res = res * 2
    return res

res = 0
n = 1
while True:
    res = res + n
    n = n + 1
    if divisorNumber(res) >= 500:
        break
print res