Initial data commit

Task/Sierpinski-triangle/JavaScript/sierpinski-triangle-1.js

@@ -0,0 +1,58 @@
+(function (order) {
+
+    // Sierpinski triangle of order N constructed as
+    // Pascal triangle of 2^N rows mod 2
+    // with 1 encoded as "▲"
+    // and 0 encoded as " "
+    function sierpinski(intOrder) {
+        return function asciiPascalMod2(intRows) {
+            return range(1, intRows - 1)
+                .reduce(function (lstRows) {
+                    var lstPrevRow = lstRows.slice(-1)[0];
+
+                    // Each new row is a function of the previous row
+                    return lstRows.concat([zipWith(function (left, right) {
+                        // The composition ( asciiBinary . mod 2 . add )
+                        // reduces to a rule from 2 parent characters
+                        // to a single child character
+
+                        // Rule 90 also reduces to the same XOR
+                        // relationship between left and right neighbours
+
+                        return left === right ? " " : "▲";
+                    }, [' '].concat(lstPrevRow), lstPrevRow.concat(' '))]);
+                }, [
+                    ["▲"] // Tip of triangle
+                ]);
+        }(Math.pow(2, intOrder))
+
+        // As centred lines, from bottom (0 indent) up (indent below + 1)
+        .reduceRight(function (sofar, lstLine) {
+            return {
+                triangle: sofar.indent + lstLine.join(" ") + "\n" +
+                    sofar.triangle,
+                indent: sofar.indent + " "
+            };
+        }, {
+            triangle: "",
+            indent: ""
+        }).triangle;
+    };
+
+    var zipWith = function (f, xs, ys) {
+            return xs.length === ys.length ? xs
+                .map(function (x, i) {
+                    return f(x, ys[i]);
+                }) : undefined;
+        },
+        range = function (m, n) {
+            return Array.apply(null, Array(n - m + 1))
+                .map(function (x, i) {
+                    return m + i;
+                });
+        };
+
+    // TEST
+    return sierpinski(order);
+
+})(4);