From 17648060a110fc4e43301053ad05290108610f22 Mon Sep 17 00:00:00 2001
From: HamSungJun <tjdwns5123@gmail.com>
Date: Tue, 29 Jun 2021 21:28:57 +0900
Subject: [PATCH] HamSungJun-938,1791,1859

---
 HamSungJun/Solution_1791.ts | 10 ++++++++++
 HamSungJun/Solution_1859.ts | 14 ++++++++++++++
 HamSungJun/Solution_938.ts  | 26 ++++++++++++++++++++++++++
 3 files changed, 50 insertions(+)
 create mode 100644 HamSungJun/Solution_1791.ts
 create mode 100644 HamSungJun/Solution_1859.ts
 create mode 100644 HamSungJun/Solution_938.ts

diff --git a/HamSungJun/Solution_1791.ts b/HamSungJun/Solution_1791.ts
new file mode 100644
index 0000000..b018ab0
--- /dev/null
+++ b/HamSungJun/Solution_1791.ts
@@ -0,0 +1,10 @@
+function findCenter (edges: number[][]): number {
+/**
+ * 첫번째 엣지의 숫자들을 Set에 매겨놓고
+ * 두번째 엣지에서 다시 등장한 버텍스가
+ * 반드시 중점 버텍스가 된다.
+ */
+  const set = new Set(edges[0])
+  const [u, v] = edges[1]
+  return set.has(u) ? u : v
+};
diff --git a/HamSungJun/Solution_1859.ts b/HamSungJun/Solution_1859.ts
new file mode 100644
index 0000000..2369bfd
--- /dev/null
+++ b/HamSungJun/Solution_1859.ts
@@ -0,0 +1,14 @@
+function sortSentence (s: string): string {
+/**
+ * 끝자리 숫자를 기준으로 정렬
+ * 조인하여 반환된 문자열에서 정규식 매칭을 통해
+ * 숫자를 전부 제거하면 정렬된 문자열만 남아 반환됨.
+ */
+  const sArr = s.split(' ')
+  sArr.sort((a, b) => {
+    const rankA = +a[a.length - 1]
+    const rankB = +b[b.length - 1]
+    return Number(rankA > rankB) - Number(rankA < rankB)
+  })
+  return sArr.join(' ').replace(/\d/g, '')
+};
diff --git a/HamSungJun/Solution_938.ts b/HamSungJun/Solution_938.ts
new file mode 100644
index 0000000..71f63fb
--- /dev/null
+++ b/HamSungJun/Solution_938.ts
@@ -0,0 +1,26 @@
+interface RangeCondition {
+    low: number;
+    high: number;
+}
+
+function rangeSumBST (root: TreeNode | null, low: number, high: number): number {
+/**
+ * 1. InOrder(Left -> Root -> Right) 으로 순회한다.
+ * 2. low <= val && <= hight 의 값이면 배열에 Push
+ * 3. 배열에 취합된 값들을 더하여 리턴.
+ */
+  const l1: number[] = []
+  recRangeSum(root, { low, high }, l1)
+  return l1.reduce((acc, curr) => (acc += curr), 0)
+};
+
+function recRangeSum (root: TreeNode | null, { low, high }: RangeCondition, list: number[]): void {
+  if (!root) return
+  recRangeSum(root.left, { low, high }, list)
+  const nodeValue = root.val
+  if (low <= nodeValue && nodeValue <= high) {
+    list.push(nodeValue)
+  }
+
+  recRangeSum(root.right, { low, high }, list)
+}