diff --git a/notes/12. 矩阵中的路径.md b/notes/12. 矩阵中的路径.md
index 15778537..cdb30e3d 100644
--- a/notes/12. 矩阵中的路径.md	
+++ b/notes/12. 矩阵中的路径.md	
@@ -1,6 +1,6 @@
 # 12. 矩阵中的路径
 
-[牛客网](https://www.nowcoder.com/practice/69fe7a584f0a445da1b6652978de5c38?tpId=13&tqId=11218&tab=answerKey&from=cyc_github)
+[Leetcode](https://leetcode.cn/problems/ju-zhen-zhong-de-lu-jing-lcof/)
 
 ## 题目描述
 
@@ -16,63 +16,39 @@
 
 <div align="center"> <img src="https://cs-notes-1256109796.cos.ap-guangzhou.myqcloud.com/dc964b86-7a08-4bde-a3d9-e6ddceb29f98.png" width="200px"> </div><br>
 
-本题的输入是数组而不是矩阵（二维数组），因此需要先将数组转换成矩阵。
-
 ```java
-public class Solution {
-    private final static int[][] next = {{0, -1}, {0, 1}, {-1, 0}, {1, 0}};
-    private int rows;
-    private int cols;
+private final static int[][] next = {{0, -1}, {0, 1}, {-1, 0}, {1, 0}};
+private int rows;
+private int cols;
 
-    public boolean hasPath (String val, int rows, int cols, String path) {
-        if (rows == 0 || cols == 0) return false;
-        this.rows = rows;
-        this.cols = cols;
-        char[] array = val.toCharArray();
-        char[][] matrix = buildMatrix(array);
-        char[] pathList = path.toCharArray();
-        boolean[][] marked = new boolean[rows][cols];
-        for (int i = 0; i < rows; i++)
-            for (int j = 0; j < cols; j++)
-                if (backtracking(matrix, pathList, marked, 0, i, j))
-                    return true;
-
-        return false;
-    }
-
-    private boolean backtracking(char[][] matrix, char[] pathList,
-                                 boolean[][] marked, int pathLen, int r, int c) {
-
-        if (pathLen == pathList.length) return true;
-        if (r < 0 || r >= rows || c < 0 || c >= cols
-                || matrix[r][c] != pathList[pathLen] || marked[r][c]) {
-
-            return false;
-        }
-        marked[r][c] = true;
-        for (int[] n : next)
-            if (backtracking(matrix, pathList, marked, pathLen + 1, r + n[0], c + n[1]))
+public boolean wordPuzzle(char[][] grid, String target) {
+    if (grid == null || grid.length == 0 || grid[0].length == 0) return false;
+    rows = grid.length;
+    cols = grid[0].length;
+    boolean[][] marked = new boolean[rows][cols];
+    char[] words = target.toCharArray();
+    for (int i = 0; i < rows; i++) {
+        for (int j = 0; j < cols; j++) {
+            if (backtracking(grid, words, marked, 0, i, j))
                 return true;
-        marked[r][c] = false;
+        }
+    }
+    return false;
+}
+
+private boolean backtracking(char[][] grid, char[] words,
+                             boolean[][] marked, int pathLen, int r, int c) {
+    if (pathLen == words.length) return true;
+    if (r < 0 || r >= rows || c < 0 || c >= cols
+            || grid[r][c] != words[pathLen] || marked[r][c]) {
         return false;
     }
-
-    private char[][] buildMatrix(char[] array) {
-        char[][] matrix = new char[rows][cols];
-        for (int r = 0, idx = 0; r < rows; r++)
-            for (int c = 0; c < cols; c++)
-                matrix[r][c] = array[idx++];
-        return matrix;
-    }
-
-    public static void main(String[] args) {
-        Solution solution = new Solution();
-        String val = "ABCESFCSADEE";
-        int rows = 3;
-        int cols = 4;
-        String path = "ABCCED";
-        boolean res = solution.hasPath(val, rows, cols, path);
-        System.out.println(res);
-    }
+    if (pathLen == words.length - 1) return true;
+    marked[r][c] = true;
+    for (int[] n : next)
+        if (backtracking(grid, words, marked, pathLen + 1, r + n[0], c + n[1]))
+            return true;
+    marked[r][c] = false;
+    return false;
 }
 ```