Solve problem 92

python/e092.py

@@ -0,0 +1,29 @@
+from functools import cache
+
+
+def euler_092():
+    count = 0
+
+    square_dict = {str(i): i * i for i in range(10)}
+    square_lookup = lambda s: square_dict[s]
+
+    @cache
+    def number_chain(n):
+        if n == 1 or n == 89:
+            return n
+        squared_digits = map(square_lookup, str(n))
+        new_n = sum(squared_digits)
+        n = number_chain(new_n)
+        return n
+
+    for n in range(1, 10**7 + 1):
+        if number_chain(n) == 89:
+            count += 1
+    return count
+
+
+if __name__ == "__main__":
+    solution = euler_092()
+    print("e092.py: " + str(solution))
+    assert(solution == 8581146)
+