54. 螺旋矩阵

src/main.rs

@@ -1,29 +1,62 @@
 struct Solution;
 impl Solution {
-    // return type: all situation, not crash situation
-    pub fn new21_game(n: i32, k: i32, max_pts: i32) -> f64 {
-        let mut mem = vec![0f64; (k + max_pts + 1) as usize];
-        for i in k .. k + max_pts + 1 {
-            mem[i as usize] = if i <= n { 1f64 } else { 0f64 };
-        }
-        let mut temp_ans = 0f64;
-        if(k - 1 >= 0)
-        {
-            let i = k - 1;
-            for j in 1..max_pts + 1 {
-                temp_ans += mem[(i + j) as usize];
+    pub fn spiral_order(matrix: Vec<Vec<i32>>) -> Vec<i32> {
+        let mut top_x = 0;
+        let mut left_y = 0;
+        let mut bottom_x = matrix.len() as i32 - 1;
+        let mut right_y = matrix[0].len() as i32 - 1;
+        let mut next_x = 0;
+        let mut next_y = 1;
+        let mut pos = (0, 0);
+
+        let mut res = vec![matrix[0][0]];
+
+        let mut next_pos = || {
+            let mut new_pos = (pos.0 + next_x, pos.1 + next_y);
+            if new_pos.0 > bottom_x || new_pos.0 < top_x || new_pos.1 > right_y || new_pos.1 < left_y {
+                (next_x, next_y) = match (next_x, next_y) {
+                    (0, 1) => {
+                        top_x += 1;
+                        (1, 0)
+                    }
+                    (1, 0) => {
+                        right_y -= 1;
+                        (0, -1)
+                    }
+                    (0, -1) => {
+                        bottom_x -= 1;
+                        (-1, 0)
+                    }
+                    (-1, 0) => {
+                        left_y += 1;
+                        (0, 1)
+                    }
+                    _ => (0, 0),
+                };
+
+                new_pos = (pos.0 + next_x, pos.1 + next_y);
+                if new_pos.0 > bottom_x
+                    || new_pos.0 < top_x
+                    || new_pos.1 > right_y
+                    || new_pos.1 < left_y
+                {
+                    return false;
+                }
             }
-            mem[i as usize] = temp_ans as f64 / max_pts as f64;
-        }
-        for i in (0..k - 1).rev() {
-            temp_ans += mem[(i + 1) as usize] - mem[(i + max_pts + 1) as usize];
-            mem[i as usize] = temp_ans as f64 / max_pts as f64;
-        }
-        mem[0]
+            pos = new_pos;
+            res.push(matrix[pos.0 as usize][pos.1 as usize]);
+            true
+        };
+        while next_pos() {}
+        res
     }
 }
 
 fn main() {
-    let sl = Solution::new21_game(21, 17, 10);
+    let sl = Solution::spiral_order(vec![
+        vec![1, 2, 3, 4],
+        vec![5, 6, 7, 8],
+        vec![9, 10, 11, 12],
+    ]);
     println!("{:?}", sl);
 }