Data commit

Task/Smith-numbers/Java/smith-numbers.java

@@ -0,0 +1,45 @@
+import java.util.*;
+
+public class SmithNumbers {
+
+    public static void main(String[] args) {
+        for (int n = 1; n < 10_000; n++) {
+            List<Integer> factors = primeFactors(n);
+            if (factors.size() > 1) {
+                int sum = sumDigits(n);
+                for (int f : factors)
+                    sum -= sumDigits(f);
+                if (sum == 0)
+                    System.out.println(n);
+            }
+        }
+    }
+
+    static List<Integer> primeFactors(int n) {
+        List<Integer> result = new ArrayList<>();
+
+        for (int i = 2; n % i == 0; n /= i)
+            result.add(i);
+
+        for (int i = 3; i * i <= n; i += 2) {
+            while (n % i == 0) {
+                result.add(i);
+                n /= i;
+            }
+        }
+
+        if (n != 1)
+            result.add(n);
+
+        return result;
+    }
+
+    static int sumDigits(int n) {
+        int sum = 0;
+        while (n > 0) {
+            sum += (n % 10);
+            n /= 10;
+        }
+        return sum;
+    }
+}