Another update from ingydotnet^djgoku

Task/Factors-of-an-integer/JavaScript/factors-of-an-integer-2.js

@@ -0,0 +1,19 @@
+// Monadic bind (chain) for lists
+function chain(xs, f) {
+  return [].concat.apply([], xs.map(f));
+}
+
+// [m..n]
+function range(m, n) {
+  return Array.apply(null, Array(n - m + 1)).map(function (x, i) {
+    return m + i;
+  });
+}
+
+function factors_naive(n) {
+  return chain( range(1, n), function (x) {       // monadic chain/bind
+    return n % x ? [] : [x];                      // monadic fail or inject/return
+  });
+}
+
+factors_naive(6)

Task/Factors-of-an-integer/JavaScript/factors-of-an-integer-3.js

@@ -0,0 +1 @@
+[1, 2, 3, 6]

Task/Factors-of-an-integer/JavaScript/factors-of-an-integer-4.js

@@ -0,0 +1,59 @@
+console.log(
+  (function (lstTest) {
+
+    // INTEGER FACTORS
+    function integerFactors(n) {
+      var rRoot = Math.sqrt(n),
+        intRoot = Math.floor(rRoot),
+
+        lows = range(1, intRoot).filter(function (x) {
+          return (n % x) === 0;
+        });
+
+      // for perfect squares, we can drop the head of the 'highs' list
+      return lows.concat(lows.map(function (x) {
+        return n / x;
+      }).reverse().slice((rRoot === intRoot) | 0));
+    }
+
+    // [m .. n]
+    function range(m, n) {
+      return Array.apply(null, Array(n - m + 1)).map(function (x, i) {
+        return m + i;
+      });
+    }
+
+    /*************************** TESTING *****************************/
+
+    // TABULATION OF RESULTS IN SPACED AND ALIGNED COLUMNS
+    function alignedTable(lstRows, lngPad, fnAligned) {
+      var lstColWidths = range(0, lstRows.reduce(function (a, x) {
+        return x.length > a ? x.length : a;
+      }, 0) - 1).map(function (iCol) {
+        return lstRows.reduce(function (a, lst) {
+          var w = lst[iCol] ? lst[iCol].toString().length : 0;
+          return (w > a) ? w : a;
+        }, 0);
+      });
+
+      return lstRows.map(function (lstRow) {
+        return lstRow.map(function (v, i) {
+          return fnAligned(v, lstColWidths[i] + lngPad);
+        }).join('')
+      }).join('\n');
+    }
+
+    function alignRight(n, lngWidth) {
+      var s = n.toString();
+      return Array(lngWidth - s.length + 1).join(' ') + s;
+    }
+
+    // TEST
+    return '\nintegerFactors(n)\n\n' + alignedTable(
+      lstTest.map(integerFactors).map(function (x, i) {
+        return [lstTest[i], '-->'].concat(x);
+      }), 2, alignRight
+    ) + '\n';
+
+  })([25, 45, 53, 64, 100, 102, 120, 12345, 32766, 32767])
+);

Task/Factors-of-an-integer/JavaScript/factors-of-an-integer-5.js

@@ -0,0 +1,12 @@
+integerFactors(n)
+
+     25  -->  1   5  25
+     45  -->  1   3   5    9   15    45
+     53  -->  1  53
+     64  -->  1   2   4    8   16    32    64
+    100  -->  1   2   4    5   10    20    25     50  100
+    102  -->  1   2   3    6   17    34    51    102
+    120  -->  1   2   3    4    5     6     8     10   12   15   20   24    30     40     60    120
+  12345  -->  1   3   5   15  823  2469  4115  12345
+  32766  -->  1   2   3    6   43    86   127    129  254  258  381  762  5461  10922  16383  32766
+  32767  -->  1   7  31  151  217  1057  4681  32767