EASY/src/easy/HappyNumber.java

fishercoder1534 · fishercoder1534 · commit f1aafadfd6e7 · 2016-09-24T22:05:52.000-07:00
diff --git a/EASY/src/easy/HappyNumber.java b/EASY/src/easy/HappyNumber.java
@@ -0,0 +1,29 @@
+package easy;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class HappyNumber {
+
+    public static boolean isHappy(int n) {
+        if(n == 1) return true;
+        Set<Integer> set = new HashSet();
+        while(n != 1){
+            String str = String.valueOf(n);
+            n = 0;
+            for(int i = 0; i < str.length(); i++){
+                int temp = Character.getNumericValue(str.charAt(i));
+                n += temp*temp;
+            }
+            if(n == 1) return true;
+            if(!set.add(n)) return false;
+        }
+        return false;
+    }
+
+    
+    public static void main(String...strings){
+       int n = 7;
+        System.out.println(isHappy(n)); 
+    }
+}
