September 2017 Update

Task/Heronian-triangles/JavaScript/heronian-triangles-3.js

@@ -1,82 +0,0 @@
-(function (n) {
-
-  var chain = function (xs, f) {                  // Monadic bind/chain
-      return [].concat.apply([], xs.map(f));
-    },
-
-    hArea = function (x, y, z) {
-      var s = (x + y + z) / 2,
-        a = s * (s - x) * (s - y) * (s - z);
-      return a ? Math.sqrt(a) : 0;
-    },
-
-    gcd = function (m, n) { return n ? gcd(n, m % n) : m; },
-
-    rng = function (m, n) {
-      return Array.apply(null, Array(n - m + 1)).map(function (x, i) {
-        return m + i;
-      });
-    },
-
-    sum = function (a, x) { return a + x; };
-
-  // DEFINING THE SORTED SUB-SET IN TERMS OF A LIST MONAD
-
-  var lstHeron = chain( rng(1, n), function (x) {
-          return chain( rng(x, n), function (y) {
-          return chain( rng(y, n), function (z) {
-
-        return (
-          (x + y > z) &&
-          gcd(gcd(x, y), z) === 1 &&            // Primitive.
-          (function () {                        // Heronian.
-            var a = hArea(x, y, z);
-            return a && (a === parseInt(a, 10))
-          })()
-        ) ? [[x, y, z]] : [];                   // Monadic inject or fail
-
-  })})}).sort(function (a, b) {
-    var dArea = hArea.apply(null, a) - hArea.apply(null, b);
-    if (dArea) return dArea;
-    else {
-      var dPerim = a.reduce(sum, 0) - b.reduce(sum, 0);
-      return dPerim ? dPerim : (a[2] - b[2]);
-    }
-  });
-
-  // OUPUT FORMATTED AS TWO WIKITABLES
-
-  var lstColumns = ['Sides Perimeter Area'.split(' ')],
-    fnData = function (lst) {
-      return [JSON.stringify(lst), lst.reduce(sum, 0), hArea.apply(null, lst)];
-    },
-    wikiTable = function (lstRows, blnHeaderRow, strStyle) {
-      return '{| class="wikitable" ' + (
-        strStyle ? 'style="' + strStyle + '"' : ''
-      ) + lstRows.map(function (lstRow, iRow) {
-        var strDelim = ((blnHeaderRow && !iRow) ? '!' : '|');
-
-        return '\n|-\n' + strDelim + ' ' + lstRow.map(function (v) {
-          return typeof v === 'undefined' ? ' ' : v;
-        }).join(' ' + strDelim + strDelim + ' ');
-      }).join('') + '\n|}';
-    };
-
-  return 'Found: ' + lstHeron.length +
-    ' primitive Heronian triangles with sides up to ' + n + '.\n\n' +
-    '(Showing first 10, sorted by increasing area, ' +
-    'perimeter, and longest side)\n\n' +
-    wikiTable(
-      lstColumns.concat(lstHeron.slice(0, 10).map(fnData)),
-      true
-    ) + '\n\n' +
-    'All primitive Heronian triangles in this range where area = 210\n' +
-    '\n(also in order of increasing perimeter and longest side)\n\n' +
-    wikiTable(
-      lstColumns.concat(lstHeron.filter(function (x) {
-        return 210 === hArea.apply(null, x);
-      }).map(fnData)),
-      true
-    ) + '\n\n';
-
-})(200);