Create 1905-count-sub-islands.js

Author: AP-Repositories

javascript/1905-count-sub-islands.js

@@ -0,0 +1,35 @@
+var countSubIslands = function(grid1, grid2) {
+    let ROWS = grid1.length, COLS = grid1[0].length;
+    let visit = new Set();
+    
+    const dfs = function(r, c) {
+        let flatCoord = r*COLS + c;
+        if (
+            r < 0
+            || c < 0
+            || r == ROWS
+            || c == COLS
+            || grid2[r][c] == 0
+            || visit.has(flatCoord)
+        )
+            return true;
+        
+        visit.add(flatCoord);
+        let res = true;
+        if(grid1[r][c] == 0)
+            res = false;
+        
+        res = dfs(r - 1, c) && res;
+        res = dfs(r + 1, c) && res;
+        res = dfs(r, c - 1) && res;
+        res = dfs(r, c + 1) && res;
+        return res;
+    };
+    
+    let count = 0;
+    for(let r = 0; r < ROWS; r++)
+        for(let c = 0; c < COLS; c++)
+            if(grid2[r][c] && !visit.has(r*COLS + c) && dfs(r, c))
+                count += 1;
+    return count;
+};