feat: add rust solution to lc problem: No.1197 (#1169)

Author: xzhseh

solution/1100-1199/1197.Minimum Knight Moves/README.md

@@ -293,6 +293,141 @@ public:
 };
 ```
 
+### **Rust**
+
+```rust
+use std::collections::VecDeque;
+
+const DIR: [(i32, i32); 8] = [(-2, 1), (2, 1), (-1, 2), (1, 2), (2, -1), (-2, -1), (1, -2), (-1, -2)];
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn min_knight_moves(x: i32, y: i32) -> i32 {
+        // The original x, y are from [-300, 300]
+        // Let's shift them to [0, 600]
+        let x: i32 = x + 300;
+        let y: i32 = y + 300;
+        let mut ret = -1;
+        let mut vis: Vec<Vec<bool>> = vec![vec![false; 618]; 618];
+        // <X, Y, Current Steps>
+        let mut q: VecDeque<(i32, i32, i32)> = VecDeque::new();
+
+        q.push_back((300, 300, 0));
+
+        while !q.is_empty() {
+            let (i, j, s) = q.front().unwrap().clone();
+            q.pop_front();
+            if i == x && j == y {
+                ret = s;
+                break;
+            }
+            Self::enqueue(&mut vis, &mut q, i, j, s);
+        }
+
+        ret
+    }
+
+    #[allow(dead_code)]
+    fn enqueue(vis: &mut Vec<Vec<bool>>, q: &mut VecDeque<(i32, i32, i32)>, i: i32, j: i32, cur_step: i32) {
+        let next_step = cur_step + 1;
+        for (dx, dy) in DIR {
+            let x = i + dx;
+            let y = j + dy;
+            if Self::check_bounds(x, y) || vis[x as usize][y as usize] {
+                // This <X, Y> pair is either out of bound, or has been visited before
+                // Just ignore this pair
+                continue;
+            }
+            // Otherwise, add the pair to the queue
+            // Also remember to update the vis vector
+            vis[x as usize][y as usize] = true;
+            q.push_back((x, y, next_step));
+        }
+    }
+
+    #[allow(dead_code)]
+    fn check_bounds(i: i32, j: i32) -> bool {
+        i < 0 || i > 600 || j < 0 || j > 600
+    }
+}
+```
+
+双向 BFS：
+
+```rust
+use std::collections::VecDeque;
+use std::collections::HashMap;
+
+const DIR: [(i32, i32); 8] = [(-2, 1), (2, 1), (-1, 2), (1, 2), (2, -1), (-2, -1), (1, -2), (-1, -2)];
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn min_knight_moves(x: i32, y: i32) -> i32 {
+        if x == 0 && y == 0 {
+            return 0;
+        }
+        // Otherwise, let's shift <X, Y> from [-300, 300] -> [0, 600]
+        let x = x + 300;
+        let y = y + 300;
+        let mut ret = -1;
+        // Initialize the two hash map, used to track if a node has been visited
+        let mut map_to: HashMap<i32, i32> = HashMap::new();
+        let mut map_from: HashMap<i32, i32> = HashMap::new();
+        // Input the original status
+        map_to.insert(601 * 300 + 300, 0);
+        map_from.insert(601 * x + y, 0);
+        let mut q_to: VecDeque<(i32, i32)> = VecDeque::new();
+        let mut q_from: VecDeque<(i32, i32)> = VecDeque::new();
+        // Initialize the two queue
+        q_to.push_back((300, 300));
+        q_from.push_back((x, y));
+
+        while !q_to.is_empty() && !q_from.is_empty() {
+            let step = if q_to.len() < q_from.len() { 
+                Self::extend(&mut map_to, &mut map_from, &mut q_to)
+            } else {
+                Self::extend(&mut map_from, &mut map_to, &mut q_from)
+            };
+            if step != -1 {
+                ret = step;
+                break;
+            }
+        }
+
+        ret
+    }
+
+    #[allow(dead_code)]
+    fn extend(map_to: &mut HashMap<i32, i32>, map_from: &mut HashMap<i32, i32>, cur_q: &mut VecDeque<(i32, i32)>) -> i32 {
+        let n = cur_q.len();
+        for _ in 0..n {
+            let (i, j) = cur_q.front().unwrap().clone();
+            cur_q.pop_front();
+            // The cur_step here must exist
+            let cur_step = map_to.get(&(601 * i + j)).unwrap().clone();
+            for (dx, dy) in DIR {
+                let x = i + dx;
+                let y = j + dy;
+                // Check if this node has been visited
+                if map_to.contains_key(&(601 * x + y)) {
+                    // Just ignore this node
+                    continue;
+                }
+                // Check if this node has been visited by the other side
+                if map_from.contains_key(&(601 * x + y)) {
+                    // We found the node
+                    return cur_step + 1 + map_from.get(&(601 * x + y)).unwrap().clone();
+                }
+                // Otherwise, update map_to and push the new node to queue
+                map_to.insert(601 * x + y, cur_step + 1);
+                cur_q.push_back((x, y));
+            }
+        }
+        -1
+    }
+}
+```
+
 ### **Go**
 
 ```go

solution/1100-1199/1197.Minimum Knight Moves/README_EN.md

@@ -272,6 +272,141 @@ public:
 };
 ```
 
+### **Rust**
+
+```rust
+use std::collections::VecDeque;
+
+const DIR: [(i32, i32); 8] = [(-2, 1), (2, 1), (-1, 2), (1, 2), (2, -1), (-2, -1), (1, -2), (-1, -2)];
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn min_knight_moves(x: i32, y: i32) -> i32 {
+        // The original x, y are from [-300, 300]
+        // Let's shift them to [0, 600]
+        let x: i32 = x + 300;
+        let y: i32 = y + 300;
+        let mut ret = -1;
+        let mut vis: Vec<Vec<bool>> = vec![vec![false; 618]; 618];
+        // <X, Y, Current Steps>
+        let mut q: VecDeque<(i32, i32, i32)> = VecDeque::new();
+
+        q.push_back((300, 300, 0));
+
+        while !q.is_empty() {
+            let (i, j, s) = q.front().unwrap().clone();
+            q.pop_front();
+            if i == x && j == y {
+                ret = s;
+                break;
+            }
+            Self::enqueue(&mut vis, &mut q, i, j, s);
+        }
+
+        ret
+    }
+
+    #[allow(dead_code)]
+    fn enqueue(vis: &mut Vec<Vec<bool>>, q: &mut VecDeque<(i32, i32, i32)>, i: i32, j: i32, cur_step: i32) {
+        let next_step = cur_step + 1;
+        for (dx, dy) in DIR {
+            let x = i + dx;
+            let y = j + dy;
+            if Self::check_bounds(x, y) || vis[x as usize][y as usize] {
+                // This <X, Y> pair is either out of bound, or has been visited before
+                // Just ignore this pair
+                continue;
+            }
+            // Otherwise, add the pair to the queue
+            // Also remember to update the vis vector
+            vis[x as usize][y as usize] = true;
+            q.push_back((x, y, next_step));
+        }
+    }
+
+    #[allow(dead_code)]
+    fn check_bounds(i: i32, j: i32) -> bool {
+        i < 0 || i > 600 || j < 0 || j > 600
+    }
+}
+```
+
+Two-end BFS:
+
+```rust
+use std::collections::VecDeque;
+use std::collections::HashMap;
+
+const DIR: [(i32, i32); 8] = [(-2, 1), (2, 1), (-1, 2), (1, 2), (2, -1), (-2, -1), (1, -2), (-1, -2)];
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn min_knight_moves(x: i32, y: i32) -> i32 {
+        if x == 0 && y == 0 {
+            return 0;
+        }
+        // Otherwise, let's shift <X, Y> from [-300, 300] -> [0, 600]
+        let x = x + 300;
+        let y = y + 300;
+        let mut ret = -1;
+        // Initialize the two hash map, used to track if a node has been visited
+        let mut map_to: HashMap<i32, i32> = HashMap::new();
+        let mut map_from: HashMap<i32, i32> = HashMap::new();
+        // Input the original status
+        map_to.insert(601 * 300 + 300, 0);
+        map_from.insert(601 * x + y, 0);
+        let mut q_to: VecDeque<(i32, i32)> = VecDeque::new();
+        let mut q_from: VecDeque<(i32, i32)> = VecDeque::new();
+        // Initialize the two queue
+        q_to.push_back((300, 300));
+        q_from.push_back((x, y));
+
+        while !q_to.is_empty() && !q_from.is_empty() {
+            let step = if q_to.len() < q_from.len() { 
+                Self::extend(&mut map_to, &mut map_from, &mut q_to)
+            } else {
+                Self::extend(&mut map_from, &mut map_to, &mut q_from)
+            };
+            if step != -1 {
+                ret = step;
+                break;
+            }
+        }
+
+        ret
+    }
+
+    #[allow(dead_code)]
+    fn extend(map_to: &mut HashMap<i32, i32>, map_from: &mut HashMap<i32, i32>, cur_q: &mut VecDeque<(i32, i32)>) -> i32 {
+        let n = cur_q.len();
+        for _ in 0..n {
+            let (i, j) = cur_q.front().unwrap().clone();
+            cur_q.pop_front();
+            // The cur_step here must exist
+            let cur_step = map_to.get(&(601 * i + j)).unwrap().clone();
+            for (dx, dy) in DIR {
+                let x = i + dx;
+                let y = j + dy;
+                // Check if this node has been visited
+                if map_to.contains_key(&(601 * x + y)) {
+                    // Just ignore this node
+                    continue;
+                }
+                // Check if this node has been visited by the other side
+                if map_from.contains_key(&(601 * x + y)) {
+                    // We found the node
+                    return cur_step + 1 + map_from.get(&(601 * x + y)).unwrap().clone();
+                }
+                // Otherwise, update map_to and push the new node to queue
+                map_to.insert(601 * x + y, cur_step + 1);
+                cur_q.push_back((x, y));
+            }
+        }
+        -1
+    }
+}
+```
+
 ### **Go**
 
 Two-end BFS:

solution/1100-1199/1197.Minimum Knight Moves/Solution.rs

@@ -0,0 +1,54 @@
+use std::collections::VecDeque;
+
+const DIR: [(i32, i32); 8] = [(-2, 1), (2, 1), (-1, 2), (1, 2), (2, -1), (-2, -1), (1, -2), (-1, -2)];
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn min_knight_moves(x: i32, y: i32) -> i32 {
+        // The original x, y are from [-300, 300]
+        // Let's shift them to [0, 600]
+        let x: i32 = x + 300;
+        let y: i32 = y + 300;
+        let mut ret = -1;
+        let mut vis: Vec<Vec<bool>> = vec![vec![false; 618]; 618];
+        // <X, Y, Current Steps>
+        let mut q: VecDeque<(i32, i32, i32)> = VecDeque::new();
+
+        q.push_back((300, 300, 0));
+
+        while !q.is_empty() {
+            let (i, j, s) = q.front().unwrap().clone();
+            q.pop_front();
+            if i == x && j == y {
+                ret = s;
+                break;
+            }
+            Self::enqueue(&mut vis, &mut q, i, j, s);
+        }
+
+        ret
+    }
+
+    #[allow(dead_code)]
+    fn enqueue(vis: &mut Vec<Vec<bool>>, q: &mut VecDeque<(i32, i32, i32)>, i: i32, j: i32, cur_step: i32) {
+        let next_step = cur_step + 1;
+        for (dx, dy) in DIR {
+            let x = i + dx;
+            let y = j + dy;
+            if Self::check_bounds(x, y) || vis[x as usize][y as usize] {
+                // This <X, Y> pair is either out of bound, or has been visited before
+                // Just ignore this pair
+                continue;
+            }
+            // Otherwise, add the pair to the queue
+            // Also remember to update the vis vector
+            vis[x as usize][y as usize] = true;
+            q.push_back((x, y, next_step));
+        }
+    }
+
+    #[allow(dead_code)]
+    fn check_bounds(i: i32, j: i32) -> bool {
+        i < 0 || i > 600 || j < 0 || j > 600
+    }
+}