Solution to problem 37

src/Python/Problem037.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+"""
+Created on 09 Apr 2021
+
+@author: David Doblas Jiménez
+@email: daviddoji@pm.me
+
+Solution for problem 37 of Project Euler
+https://projecteuler.net/problem=37
+"""
+
+from itertools import product
+from utils import timeit, is_prime
+
+
+
+@timeit("Problem 37")
+def compute():
+    """
+    The number 3797 has an interesting property. Being prime itself, it is
+    possible to continuously remove digits from left to right, and remain
+    prime at each stage: 3797, 797, 97, and 7.
+    Similarly we can work from right to left: 3797, 379, 37, and 3.
+
+    Find the sum of the only eleven primes that are both truncatable from left
+    to right and right to left.
+
+    NOTE: 2, 3, 5, and 7 are not considered to be truncatable primes.
+    """
+
+    primes, ans = [], 0
+    for i in range(2,7):
+        candidates = product([1,2,3,5,7,9], repeat=i)
+        for t in candidates:
+            primes.append(''.join([str(d) for d in t]))
+
+    for p in primes:
+        trunc = True
+        if not is_prime(int(p)):
+            trunc = False
+            continue
+        for i in range(1, len(p)):
+            if not is_prime(int(p[i:])):
+                trunc = False
+                break
+            if not is_prime(int(p[:i])):
+                trunc = False
+                break
+        if trunc:
+            ans += int(p)
+    
+    return ans
+
+
+if __name__ == "__main__":
+
+    print(f"Result for Problem 37: {compute()}")