快乐数字

crossoverJie · crossoverJie · commit 1fc46aacbcc8 · 2018-01-04T17:34:42.000+08:00
diff --git a/src/main/java/com/crossoverjie/algorithm/HappyNum.java b/src/main/java/com/crossoverjie/algorithm/HappyNum.java
@@ -0,0 +1,44 @@
+package com.crossoverjie.algorithm;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Function: 判断一个数字是否为快乐数字 19 就是快乐数字  11就不是快乐数字
+ *
+ * @author crossoverJie
+ *         Date: 04/01/2018 14:12
+ * @since JDK 1.8
+ */
+public class HappyNum {
+
+    public boolean isHappy(int number) {
+        Set<Integer> set = new HashSet<>(30);
+        while (number != 1) {
+            int sum = 0;
+            while (number > 0) {
+                //计算当前值的每位数的平方 相加的和 在放入set中，如果存在相同的就认为不是 happy数字
+                sum += (number % 10) * (number % 10);
+                number = number / 10;
+            }
+            if (set.contains(sum)) {
+                return false;
+            } else {
+                set.add(sum);
+            }
+            number = sum;
+        }
+        return true;
+    }
+
+
+    public static void main(String[] args) {
+        int num = 345;
+        int i = num % 10;
+        int i1 = num / 10;
+        int i2 = i1 / 10;
+        System.out.println(i);
+        System.out.println(i1);
+        System.out.println(i2);
+    }
+}
diff --git a/src/test/java/com/crossoverjie/algorithm/HappyNumTest.java b/src/test/java/com/crossoverjie/algorithm/HappyNumTest.java
@@ -0,0 +1,28 @@
+package com.crossoverjie.algorithm;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class HappyNumTest {
+    @Test
+    public void isHappy() throws Exception {
+        HappyNum happyNum = new HappyNum() ;
+        boolean happy = happyNum.isHappy(19);
+        Assert.assertEquals(happy,true);
+    }
+
+    @Test
+    public void isHappy2() throws Exception {
+        HappyNum happyNum = new HappyNum() ;
+        boolean happy = happyNum.isHappy(11);
+        Assert.assertEquals(happy,false);
+    }
+
+    @Test
+    public void isHappy3() throws Exception {
+        HappyNum happyNum = new HappyNum() ;
+        boolean happy = happyNum.isHappy(100);
+        System.out.println(happy);
+    }
+
+}
