EularProject 42:單詞解碼出來的三角形數
Coded triangle numbers
Problem 42
The nth term of the sequence of triangle numbers is given by, tn = ?n(n+1); so the first ten triangle numbers are:
1, 3, 6, 10, 15, 21, 28, 36, 45, 55, …
By converting each letter in a word to a number corresponding to its alphabetical position and adding these values we form a word value. For example, the word value for SKY is 19 + 11 + 25 = 55 = t10. If the word value is a triangle number then we shall call the word a triangle word.
Using words.txt (right click and ‘Save Link/Target As…’), a 16K text file containing nearly two-thousand common English words, how many are triangle words?
Answer:
162
Completed on Thu, 30 Jul 2015, 09:06
from math import sqrt
def IsTriangleNumber(word):
data=0
for i in word:
data+=ord(i)-ord(‘A‘)+1
k=int(sqrt(data*2))
if data*2==k*(k+1):
return 1
else:
return 0
count=0
for line in open(‘p042_words.txt‘,‘r‘):
line=line.strip(‘\n‘).split(",")
for word in line:
word=word.strip("\"")
count+=IsTriangleNumber(word)
print(count)
EularProject 42:單詞解碼出來的三角形數