Update index.html

index.html

@@ -47,6 +47,7 @@
                     for (let j = 0; j < this.num_cols; j++) {
                         // check winner at cell i, j
                         var p = this.get(i, j);
+                        if (p == 0) continue;
                         for (let dxy of [[1, 0], [0, 1], [1, 1], [-1, 1]]) {
                             var count = 0;
                             for (let k = 1; k <= 4; k++) {