Solution to problem 42

src/Python/Problem042.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+"""
+Created on 26 Jul 2021
+
+@author: David Doblas Jiménez
+@email: daviddoji@pm.me
+
+Solution for problem 42 of Project Euler
+https://projecteuler.net/problem=42
+"""
+
+from utils import timeit
+
+
+@timeit("Problem 42")
+def compute():
+    """
+    The nth term of the sequence of triangle numbers is given by, tn = ½n(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, a 16K text file containing nearly two-thousand common English words,
+    how many are triangle words?
+    """
+
+    def triangle_number(num):
+        return int(0.5*num*(num+1))
+
+    def word_to_value(word):
+        return sum(ord(letter)-64 for letter in word)
+    
+    triangular_numbers = [triangle_number(n) for n in range(27)]
+    ans = 0
+    with open("files/Problem42.txt", "r") as f:
+        words = f.readline().strip('"').split('","')
+        for word in words:
+            if word_to_value(word) in triangular_numbers:
+                ans += 1
+
+    return ans
+
+if __name__ == "__main__":
+
+    print(f"Result for Problem 42: {compute()}")