Merge remote-tracking branch 'upstream/master'

1 files changed, 60 insertions, 0 deletions

diff --git a/challenge-077/abigail/node/ch-2.js b/challenge-077/abigail/node/ch-2.js
new file mode 100644
index 0000000000..ee04d5c605
--- /dev/null
+++ b/challenge-077/abigail/node/ch-2.js
@@ -0,0 +1,60 @@
+//
+// Exercise:
+//    You are given m x n character matrix consists of O and X only.
+//    Write a script to count the total number of X surrounded by O only.
+//    Print 0 if none found.
+//
+
+//
+// Read in the board:
+//    - Read STDIN
+//    - Split by newlines
+//    - Split each line on spaces
+//    - Map an 'X' to a 1, 'O' to a 0.
+//    - Add a 0 to the beginning and end of each line.
+//
+let fs    = require ("fs");
+let board = fs . readFileSync (0) . toString () . trim () . split ("\n") .
+            map (line => (line . split (" ")) . map (c => c == "X" ? 1 : 0)) .
+            map (line => ([0] . concat (line) . concat ([0])));
+
+//
+// Add top and bottom with 0s
+//
+board . push    (board [0] . map (x => 0));
+board . unshift (board [0] . map (x => 0));
+
+let count = 0;
+
+//
+// Iterate over the cells of the board board, skipping cells on the edge
+// (as we added them). For each 1, check the 8 cells surrounding the cell
+// (this will never be outside of the board). If one of the neighbouring
+// cells is a 1, move on the next cell. If no neighbouring cell is 1,
+// we add 1 to the count.
+//
+for (let x = 1; x < board . length - 1; x ++) {
+  ELEMENT:
+    for (let y = 1; y < board [x] . length - 1; y ++) {
+        if (!board [x] [y]) {
+            continue;
+        }
+        for (let dx = -1; dx <= 1; dx ++) {
+            for (let dy = -1; dy <= 1; dy ++) {
+                if (dx == 0 && dy == 0) {
+                    continue;
+                }
+                if (board [x + dx] [y + dy]) {
+                    continue ELEMENT;
+                }
+            }
+        }
+        count ++;
+    }
+}
+
+
+//
+// Print the results.
+//
+console . log (count);