添加 0037.解数独 Rust版本

添加 0037.解数独 Rust版本

problems/0037.解数独.md

@@ -488,6 +488,52 @@ function solveSudoku(board: string[][]): void {
 };
 ```
 
+### Rust
+
+```Rust
+impl Solution {
+    fn is_valid(row: usize, col: usize, val: char, board: &mut Vec<Vec<char>>) -> bool{
+        for i in 0..9 {
+            if board[row][i] == val { return false; }
+        }
+        for j in 0..9 {
+            if board[j][col] == val {
+                return false;
+            }
+        }
+        let  start_row = (row / 3) * 3;
+        let  start_col = (col / 3) * 3;
+        for i in start_row..(start_row + 3) {
+            for j in start_col..(start_col + 3) {
+                if board[i][j] == val { return false; }
+            }
+        }
+        return true;
+    }
+
+    fn backtracking(board: &mut Vec<Vec<char>>) -> bool{
+        for i in 0..board.len() {
+            for j in 0..board[0].len() {
+                if board[i][j] != '.' { continue; }
+                for k in '1'..='9' {
+                    if Self::is_valid(i, j, k, board) {
+                        board[i][j] = k;
+                        if Self::backtracking(board) { return true; }
+                        board[i][j] = '.';
+                    }
+                }
+                return false;
+            }
+        }
+        return true;
+    }
+
+    pub fn solve_sudoku(board: &mut Vec<Vec<char>>) {
+        Self::backtracking(board);
+    }
+}
+```
+
 ### C 
 
 ```C