diff --git a/notes/剑指 offer 题解.md b/notes/剑指 offer 题解.md
index c5fdda86..26cbd7b8 100644
--- a/notes/剑指 offer 题解.md	
+++ b/notes/剑指 offer 题解.md	
@@ -429,33 +429,39 @@ public int minNumberInRotateArray(int[] array) {
 
 ```java
 private int[][] next = {{0, -1}, {0, 1}, {-1, 0}, {1, 0}};
-public boolean hasPath(char[] matrix, int rows, int cols, char[] str){
-    if(rows == 0 || cols == 0) return false;
-    char[][] m = new char[rows][cols];
-    for(int i = 0, idx = 0; i < rows; i++) {
-        for(int j = 0; j < cols; j++) {
-            m[i][j] = matrix[idx++];
+private int rows;
+private int cols;
+
+public boolean hasPath(char[] matrix, int rows, int cols, char[] str) {
+    if (rows == 0 || cols == 0) return false;
+    this.rows = rows;
+    this.cols = cols;
+    // һάÊý×éÖؽ¨¶þά¾ØÕó
+    char[][] newMatrix = new char[rows][cols];
+    for (int i = 0, idx = 0; i < rows; i++) {
+        for (int j = 0; j < cols; j++) {
+            newMatrix[i][j] = matrix[idx++];
         }
     }
-
-    for(int i = 0; i < rows; i++) {
-        for(int j = 0; j < cols; j ++) {
-            if(backtracking(m, rows, cols, str, new boolean[rows][cols], 0, i, j)) return true;
+    for (int i = 0; i < rows; i++) {
+        for (int j = 0; j < cols; j++) {
+            if (backtracking(newMatrix, str, new boolean[rows][cols], 0, i, j)) return true;
         }
     }
     return false;
 }
 
-private boolean backtracking(char[][] m, int rows, int cols, char[] str, boolean[][] used, int path, int r, int c) {
-    if(path == str.length) return true;
-    if(r < 0 || r >= rows || c < 0 || c >= cols) return false;
-    if(m[r][c] != str[path]) return false;
-    if(used[r][c]) return false;
-    used[r][c] = true;
-    for(int i = 0; i < next.length; i++) {
-        if(backtracking(m, rows, cols, str, used, path + 1, r + next[i][0], c + next[i][1])) return true;
+private boolean backtracking(char[][] matrix, char[] str, boolean[][] used, int pathLen, int curR, int curC) {
+    if (pathLen == str.length) return true;
+    if (curR < 0 || curR >= rows || curC < 0 || curC >= cols) return false;
+    if (matrix[curR][curC] != str[pathLen]) return false;
+    if (used[curR][curC]) return false;
+    used[curR][curC] = true;
+    for (int i = 0; i < next.length; i++) {
+        if (backtracking(matrix, str, used, pathLen + 1, curR + next[i][0], curC + next[i][1]))
+            return true;
     }
-    used[r][c] = false;
+    used[curR][curC] = false;
     return false;
 }
 ```