Create 1905-count-sub-islands.js

Author: everthis

1905-count-sub-islands.js

@@ -0,0 +1,25 @@
+/**
+ * @param {number[][]} grid1
+ * @param {number[][]} grid2
+ * @return {number}
+ */
+const countSubIslands = function(grid1, grid2) {
+    let m = grid2.length, n = grid2[0].length, res = 0;
+    for (let i = 0; i < m; i++) {
+        for (let j = 0; j < n; j++) {
+            if (grid2[i][j] === 1) res += dfs(grid1, grid2, i, j);                 
+        }
+    }
+    return res;  
+};
+
+function dfs(B, A, i, j) {
+    let m = A.length, n = A[0].length, res = 1;
+    if (i < 0 || i == m || j < 0 || j == n || A[i][j] == 0) return 1;
+    A[i][j] = 0;
+    res &= dfs(B, A, i - 1, j);
+    res &= dfs(B, A, i + 1, j);
+    res &= dfs(B, A, i, j - 1);
+    res &= dfs(B, A, i, j + 1);
+    return res & B[i][j];
+}