feat: resovled

Author: jtr109

max_area_of_island/src/lib.rs

@@ -1,13 +1,56 @@
 pub struct Solution {}
 
 impl Solution {
-    pub fn max_area_of_island(grid: Vec<Vec<i32>>) -> i32 {}
+    pub fn max_area_of_island(grid: Vec<Vec<i32>>) -> i32 {
+        let mut grid = grid;
+        let mut max = 0;
+        for i in 0..grid.len() {
+            for j in 0..grid[0].len() {
+                max = max.max(Self::cal_area(&mut grid, i as i32, j as i32));
+            }
+        }
+        max
+    }
+
+    fn cal_area(grid: &mut Vec<Vec<i32>>, i: i32, j: i32) -> i32 {
+        let mut area = 0;
+        if grid[i as usize][j as usize] == 0 {
+            return area;
+        }
+        grid[i as usize][j as usize] = 0;
+        area += 1;
+        for (r, c) in vec![(i - 1, j), (i, j - 1), (i, j + 1), (i + 1, j)] {
+            if r < 0 || r == grid.len() as i32 || c < 0 || c == grid[0].len() as i32 {
+                continue;
+            }
+            area += Self::cal_area(grid, r, c);
+        }
+        area
+    }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
+    #[test]
+    fn test_cal_area() {
+        let grid = [
+            [0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0],
+            [0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0],
+            [0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0],
+            [0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0],
+            [0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0],
+            [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0],
+            [0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0],
+            [0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0],
+        ];
+        let mut grid = grid.iter().map(|row| row.to_vec()).collect();
+        assert_eq!(Solution::cal_area(&mut grid, 0, 2), 1);
+        assert_eq!(Solution::cal_area(&mut grid, 0, 7), 4);
+        assert_eq!(Solution::cal_area(&mut grid, 1, 7), 0);
+    }
+
     #[test]
     fn example_1() {
         let grid = [
@@ -20,11 +63,9 @@ mod tests {
             [0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0],
             [0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0],
         ];
+        let grid = grid.iter().map(|row| row.to_vec()).collect();
         let expected = 6;
-        assert_eq!(
-            Solution::max_area_of_island(grid.iter().map(|row| row.to_vec()).collect()),
-            expected
-        );
+        assert_eq!(Solution::max_area_of_island(grid), expected);
     }
 
     #[test]