Problem 50 - Which prime, below one-million, can be written as the sum of the most consecutive primes?

링크

The prime 41, can be written as the sum of six consecutive primes:

41 = 2 + 3 + 5 + 7 + 11 + 13

This is the longest sum of consecutive primes that adds to a prime below one-hundred.

The longest sum of consecutive primes below one-thousand that adds to a prime, contains 21 terms, and is equal to 953.

Which prime, below one-million, can be written as the sum of the most consecutive primes?

python

limit = 1000000 isPrime = [True] * limit isPrime[0] = isPrime[1] = False for i in range(2, int(round(limit**0.5))+1): if isPrime[i]: isPrime[2*i:limit:i] = [False] * ((limit-1)/i-1) primes = [x for x in range(2, limit) if isPrime[x]] s = e = total = ee = te = maxlen = maxsum = 0 while s < limit / 20: while e < len(primes) and total + primes[e] < limit: total += primes[e] if total > 0 and isPrime[total]: ee = e te = total e += 1 e = ee total = te if e - s > maxlen: maxlen = e - s maxsum = total total -= primes[s] s += 1 print maxsum