20240708 Finished

src/problem/mod.rs

@@ -170,3 +170,4 @@ mod p77_combinations;
 mod p46_permutations;
 mod p39_combination_sum;
 mod p22_generate_parentheses;
+mod p79_word_search;

src/problem/p79_word_search.rs

@@ -0,0 +1,78 @@
+/**
+ * [79] Word Search
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+
+impl Solution {
+    pub fn exist(board: Vec<Vec<char>>, word: String) -> bool {
+        let word: Vec<char> = word.chars().collect();
+       
+        let (m, n) = (board.len(), board[0].len());
+
+        let mut visited = vec![vec![false;n];m];
+        for i in 0..m {
+            for j in 0..n {
+                if board[i][j] == word[0] {
+                    if Self::search(&board, &word, &mut visited, i as i32, j as i32, 0) {
+                        return true;
+                    }
+                }
+            }
+        }
+
+        false
+    }
+
+    fn search(board: &Vec<Vec<char>>, word: &Vec<char>, visited: &mut Vec<Vec<bool>>, x: i32, y: i32, pos: usize) -> bool {
+        if pos == word.len() {
+            return true;
+        }
+
+        let (m, n) = (board.len() as i32, board[0].len() as i32);
+
+        if x < 0 || x >= m || y < 0 || y >= n {
+            return false;
+        }
+        
+        let (x_pos, y_pos) = (x as usize, y as usize);
+        
+        if visited[x_pos][y_pos] {
+            return false;
+        }
+
+        visited[x_pos][y_pos] = true;
+        if board[x_pos][y_pos] == word[pos] {
+            if Self::search(board, word, visited, x + 1, y, pos + 1) {
+                return true;
+            }
+
+            if Self::search(board, word, visited, x - 1, y, pos + 1) {
+                return true;
+            }
+
+            if Self::search(board, word, visited, x, y + 1, pos + 1) {
+                return true;
+            }
+
+            if Self::search(board, word, visited, x, y - 1, pos + 1) {
+                return true;
+            }
+        }
+        visited[x_pos][y_pos] = false;
+
+        false
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_79() {}
+}