.\1145.binary-tree-coloring-game ok

侯利朋 · 侯利朋 · commit c8972d34b57c · 2019-08-29T12:46:16.000+08:00
diff --git a/1145.binary-tree-coloring-game.go b/1145.binary-tree-coloring-game.go
@@ -0,0 +1,62 @@
+/*
+ * @lc app=leetcode id=1145 lang=golang
+ *
+ * [1145] Binary Tree Coloring Game
+ */
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+// 0 ms
+// 二手着色的最佳位置是 x的父节点，左，右子节点中节点数最多的那个
+func btreeGameWinningMove(root *TreeNode, n int, x int) bool {
+	// find x
+	nodeX := findnode(root, x)
+	lNodes := nodes(nodeX.Left)
+	rNodes := nodes(nodeX.Right)
+	pNodes := n - lNodes - rNodes - 1
+	return max3(lNodes, rNodes, pNodes) > n/2
+}
+
+// TODO find 和 计算节点个数，两个函数可以合并
+func findnode(root *TreeNode, x int) *TreeNode {
+	if root == nil {
+		return nil
+	}
+	if root.Val == x {
+		return root
+	}
+	if node := findnode(root.Left, x); node != nil {
+		return node
+	}
+	return findnode(root.Right, x)
+}
+
+// 返回root为根的树的节点个数
+func nodes(root *TreeNode) int {
+	if root == nil {
+		return 0
+	}
+	return 1 + nodes(root.Left) + nodes(root.Right)
+}
+
+func max3(a, b, c int) int {
+	if a >= b && a >= c {
+		return a
+	} else if b >= a && b >= c {
+		return b
+	}
+	return c
+}
