内容目录
Distinct primes factors
Problem 47
The first two consecutive numbers to have two distinct prime factors are:
14 = 2 7
15 = 3 5
The first three consecutive numbers to have three distinct prime factors are:
644 = 2² 7 23
645 = 3 5 43
646 = 2 17 19.
Find the first four consecutive integers to have four distinct prime factors. What is the first of these numbers?
本题考察Python中数组的运用:
n=1000000 a=[0 for i in range(n+1)] i=2 while i<=n: if (a[i]==0): j=2*i while j<n: a[j]=a[j]+1 j+=i i+=1 for i in range(1,n+1-3): if (a[i]==4 and a[i+1]==4 and a[i+2]==4 and a[i+3]==4): print i