auto commit

notes/12. 矩阵中的路径.md

@@ -1,6 +1,6 @@
 # 12. 矩阵中的路径
 
-[NowCoder](https://www.nowcoder.com/practice/c61c6999eecb4b8f88a98f66b273a3cc?tpId=13&tqId=11218&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking&from=cyc_github)
+[牛客网](https://www.nowcoder.com/practice/69fe7a584f0a445da1b6652978de5c38?tpId=13&tqId=11218&tab=answerKey&from=cyc_github)
 
 ## 题目描述
 
@@ -19,46 +19,60 @@
 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
-private final static int[][] next = {{0, -1}, {0, 1}, {-1, 0}, {1, 0}};
-private int rows;
-private int cols;
+public class Solution {
+    private final static int[][] next = {{0, -1}, {0, 1}, {-1, 0}, {1, 0}};
+    private int rows;
+    private int cols;
 
-public boolean hasPath(char[] array, int rows, int cols, char[] str) {
-    if (rows == 0 || cols == 0) return false;
-    this.rows = rows;
-    this.cols = cols;
-    boolean[][] marked = new boolean[rows][cols];
-    char[][] matrix = buildMatrix(array);
-    for (int i = 0; i < rows; i++)
-        for (int j = 0; j < cols; j++)
-            if (backtracking(matrix, str, marked, 0, i, j))
-                return true;
-
-    return false;
-}
-
-private boolean backtracking(char[][] matrix, char[] str,
-                             boolean[][] marked, int pathLen, int r, int c) {
-
-    if (pathLen == str.length) return true;
-    if (r < 0 || r >= rows || c < 0 || c >= cols
-            || matrix[r][c] != str[pathLen] || marked[r][c]) {
+    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;
     }
-    marked[r][c] = true;
-    for (int[] n : next)
-        if (backtracking(matrix, str, marked, pathLen + 1, r + n[0], c + n[1]))
-            return true;
-    marked[r][c] = false;
-    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;
+    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]))
+                return true;
+        marked[r][c] = false;
+        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);
+    }
 }
 ```