Merge pull request #2805 from rmrt1n/200

Create 0200-number-of-islands.rs

Author: felivalencia3

rust/0200-number-of-islands.rs

@@ -0,0 +1,36 @@
+impl Solution {
+    pub fn num_islands(grid: Vec<Vec<char>>) -> i32 {
+        fn dfs(grid: &mut Vec<Vec<char>>, x: i32, y: i32) {
+            if x < 0
+                || y < 0
+                || x >= grid.len() as i32
+                || y >= grid[0].len() as i32
+                || grid[x as usize][y as usize] == '0'
+            {
+                return;
+            }
+
+            grid[x as usize][y as usize] = '0';
+
+            let directions: [(i32, i32); 4] = [(0, 1), (1, 0), (0, -1), (-1, 0)];
+
+            for (add_x, add_y) in directions {
+                dfs(grid, x + add_x, y + add_y);
+            }
+        }
+
+        let mut count = 0;
+        let mut new_grid = grid.clone();
+
+        for x in 0..grid.len() {
+            for y in 0..grid[0].len() {
+                if new_grid[x][y] == '1' {
+                    count += 1;
+                    dfs(&mut new_grid, x as i32, y as i32);
+                }
+            }
+        }
+
+        count
+    }
+}