add 1315

fishercoder1534 · fishercoder1534 · commit 1e77cf3972d2 · 2020-02-05T07:43:40.000-08:00
diff --git a/README.md b/README.md
@@ -17,6 +17,7 @@ _If you like this project, please leave me a star._ &#9733;
 |1329|[Sort the Matrix Diagonally](https://leetcode.com/problems/sort-the-matrix-diagonally/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1329.java) | |Medium||
 |1323|[Maximum 69 Number](https://leetcode.com/problems/maximum-69-number/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1323.java) | |Easy|Math|
 |1317|[Convert Integer to the Sum of Two No-Zero Integers](https://leetcode.com/problems/convert-integer-to-the-sum-of-two-no-zero-integers/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1317.java) | |Easy||
+|1315|[Sum of Nodes with Even-Valued Grandparent](https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1315.java) | |Medium|Tree, DFS|
 |1313|[Decompress Run-Length Encoded List](https://leetcode.com/problems/decompress-run-length-encoded-list/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1313.java) | |Easy|Array|
 |1305|[All Elements in Two Binary Search Trees](https://leetcode.com/problems/all-elements-in-two-binary-search-trees/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1305.java) | |Medium||
 |1304|[Find N Unique Integers Sum up to Zero](https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1304.java) | |Easy||
diff --git a/src/main/java/com/fishercoder/solutions/_1315.java b/src/main/java/com/fishercoder/solutions/_1315.java
@@ -0,0 +1,54 @@
+package com.fishercoder.solutions;
+
+import com.fishercoder.common.classes.TreeNode;
+
+/**
+ * 1315. Sum of Nodes with Even-Valued Grandparent
+ *
+ * Given a binary tree, return the sum of values of nodes with even-valued grandparent.
+ * (A grandparent of a node is the parent of its parent, if it exists.)
+ * If there are no nodes with an even-valued grandparent, return 0.
+ *
+ * Example 1:
+ *                          6
+ *                        /  \
+ *                       7    8
+ *                      / \  / \
+ *                     2  7 1   3
+ *                    /  / \     \
+ *                   9   1 4     5
+ *
+ * Input: root = [6,7,8,2,7,1,3,9,null,1,4,null,null,null,5]
+ * Output: 18
+ * Explanation: The red nodes are the nodes with even-value grandparent while the blue nodes are the even-value grandparents.
+ *
+ * Constraints:
+ * The number of nodes in the tree is between 1 and 10^4.
+ * The value of nodes is between 1 and 100.
+ * */
+public class _1315 {
+    public static class Solution1 {
+        public int sumEvenGrandparent(TreeNode root) {
+            if (root == null) {
+                return 0;
+            }
+            return dfs(root, root.left, 0) + dfs(root, root.right, 0);
+        }
+
+        private int dfs(TreeNode grandparent, TreeNode parent, int sum) {
+            if (grandparent == null || parent == null) {
+                return sum;
+            }
+            if (grandparent.val % 2 == 0 && parent.left != null) {
+                sum += parent.left.val;
+            }
+            if (grandparent.val % 2 == 0 && parent.right != null) {
+                sum += parent.right.val;
+            }
+            sum = dfs(parent, parent.left, sum);
+            sum = dfs(parent, parent.right, sum);
+            return sum;
+        }
+
+    }
+}
diff --git a/src/test/java/com/fishercoder/_1315Test.java b/src/test/java/com/fishercoder/_1315Test.java
@@ -0,0 +1,28 @@
+package com.fishercoder;
+
+import com.fishercoder.common.classes.TreeNode;
+import com.fishercoder.common.utils.TreeUtils;
+import com.fishercoder.solutions._1315;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.junit.Assert.assertEquals;
+
+public class _1315Test {
+    private static _1315.Solution1 solution1;
+    private static TreeNode root;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1315.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        root = TreeUtils.constructBinaryTree(Arrays.asList(6, 7, 8, 2, 7, 1, 3, 9, null, 1, 4, null, null, null, 5));
+        TreeUtils.printBinaryTree(root);
+        assertEquals(18, solution1.sumEvenGrandparent(root));
+    }
+}
