aparler/RosettaCodeData
1
0
Fork 0
Code Issues 12 Pull requests 3 Projects Releases Packages Wiki Activity Actions

September 2017 Update

Browse source
This commit is contained in:
Ingy döt Net 2017-09-23 10:01:46 +02:00
parent bba7bfd280
commit ba8067c3b7
14570 changed files with 153136 additions and 63871 deletions
Download patch file Download diff file Expand all files Collapse all files

132
Task/Pascals-triangle/JavaScript/pascals-triangle-2.js
View file

@ -1,63 +1,79 @@
(function (n) {
'use strict';
// A Pascal triangle of n rows
// PASCAL TRIANGLE --------------------------------------------------------
// pascal :: Int -> [[Int]]
function pascal(n) {
return range(1, n - 1)
.reduce(function (a) {
var lstPreviousRow = a.slice(-1)[0];
return a
.concat(
[zipWith(
function (a, b) {
return a + b
},
[0].concat(lstPreviousRow),
lstPreviousRow.concat(0)
)]
);
}, [[1]]);
}
return foldl(function (a) {
var xs = a.slice(-1)[0]; // Previous row
return append(a, [zipWith(
function (a, b) {
return a + b;
},
append([0], xs),
append(xs, [0])
)]);
}, [
[1] // Initial seed row
], enumFromTo(1, n - 1));
};
// GENERIC FUNCTIONS ------------------------------------------------------
// GENERIC FUNCTIONS
// (++) :: [a] -> [a] -> [a]
function append(xs, ys) {
return xs.concat(ys);
};
// enumFromTo :: Int -> Int -> [Int]
function enumFromTo(m, n) {
return Array.from({
length: Math.floor(n - m) + 1
}, function (_, i) {
return m + i;
});
};
// foldl :: (b -> a -> b) -> b -> [a] -> b
function foldl(f, a, xs) {
return xs.reduce(f, a);
};
// foldr (a -> b -> b) -> b -> [a] -> b
function foldr(f, a, xs) {
return xs.reduceRight(f, a);
};
// map :: (a -> b) -> [a] -> [b]
function map(f, xs) {
return xs.map(f);
};
// min :: Ord a => a -> a -> a
function min(a, b) {
return b < a ? b : a;
};
// zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
function zipWith(f, xs, ys) {
return xs.length === ys.length ? (
xs.map(function (x, i) {
return f(x, ys[i]);
})
) : undefined;
}
return Array.from({
length: min(xs.length, ys.length)
}, function (_, i) {
return f(xs[i], ys[i]);
});
};
// range :: Int -> Int -> [Int]
function range(m, n) {
return Array.apply(null, Array(n - m + 1))
.map(function (x, i) {
return m + i;
});
}
// TEST
// TEST and FORMAT --------------------------------------------------------
var lstTriangle = pascal(n);
// FORMAT OUTPUT AS WIKI TABLE
// [[a]] -> bool -> s -> s
function wikiTable(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 '{| 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 + ' ');
@ -66,29 +82,21 @@
}
var lstLastLine = lstTriangle.slice(-1)[0],
lngBase = (lstLastLine.length * 2) - 1,
lngBase = lstLastLine.length * 2 - 1,
nWidth = lstLastLine.reduce(function (a, x) {
var d = x.toString()
.length;
return d > a ? d : a;
}, 1) * lngBase;
return [
wikiTable(
lstTriangle.map(function (lst) {
return lst.join(';;')
.split(';');
})
.map(function (line, i) {
var lstPad = Array((lngBase - line.length) / 2);
return lstPad.concat(line)
.concat(lstPad);
}),
false,
'text-align:center;width:' + nWidth + 'em;height:' + nWidth +
'em;table-layout:fixed;'
),
JSON.stringify(lstTriangle)
].join('\n\n');
return [wikiTable(lstTriangle.map(function (lst) {
return lst.join(';;')
.split(';');
})
.map(function (line, i) {
var lstPad = Array((lngBase - line.length) / 2);
return lstPad.concat(line)
.concat(lstPad);
}), false, 'text-align:center;width:' + nWidth + 'em;height:' + nWidth +
'em;table-layout:fixed;'), JSON.stringify(lstTriangle)].join('\n\n');
})(7);