Create 1905-count-sub-islands.js

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;
+};