From 16350b65e4634a19b3cd5f9ab9c44281bf56bbd4 Mon Sep 17 00:00:00 2001
From: curtishd <131777542+curtishd@users.noreply.github.com>
Date: Wed, 27 Mar 2024 21:47:34 +0800
Subject: [PATCH] Add kotlin code block for array.md and
 backtracking_algorithm.md. (#1185)

---
 docs/chapter_array_and_linkedlist/array.md    |  4 +++-
 .../backtracking_algorithm.md                 | 22 ++++++++++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/docs/chapter_array_and_linkedlist/array.md b/docs/chapter_array_and_linkedlist/array.md
index 0625316ff..bf3ee8250 100755
--- a/docs/chapter_array_and_linkedlist/array.md
+++ b/docs/chapter_array_and_linkedlist/array.md
@@ -108,7 +108,9 @@
 === "Kotlin"
 
     ```kotlin title="array.kt"
-
+    /* 初始化数组 */
+    var arr = IntArray(5) // { 0, 0, 0, 0, 0 }
+    var nums = intArrayOf(1, 3, 2, 5, 4)
     ```
 
 === "Zig"
diff --git a/docs/chapter_backtracking/backtracking_algorithm.md b/docs/chapter_backtracking/backtracking_algorithm.md
index f3a3da5a1..ca4b19885 100644
--- a/docs/chapter_backtracking/backtracking_algorithm.md
+++ b/docs/chapter_backtracking/backtracking_algorithm.md
@@ -380,7 +380,27 @@
 === "Kotlin"
 
     ```kotlin title=""
-
+    /* 回溯算法框架 */
+    fun backtrack(state: State?, choices: List<Choice?>, res: List<State?>?) {
+        // 判断是否为解
+        if (isSolution(state)) {
+            // 记录解
+            recordSolution(state, res)
+            // 不再继续搜索
+            return
+        }
+        // 遍历所有选择
+        for (choice in choices) {
+            // 剪枝：判断选择是否合法
+            if (isValid(state, choice)) {
+                // 尝试：做出选择，更新状态
+                makeChoice(state, choice)
+                backtrack(state, choices, res)
+                // 回退：撤销选择，恢复到之前的状态
+                undoChoice(state, choice)
+            }
+        }
+    }
     ```
 
 === "Zig"