I have a puzzle,
input
var a = ['a', 'b', 'c', 'd'],
b = [1, 0, 3, 2];
output
['b', 'a', 'd', 'c']
My solution looks like this
function _sort(array, rules) {
var i, len = rules.length, res = []
if (array.length !== len) {
return null;
}
for (i = 0; i < len; i++) {
res[rules[i]] = array[i];
}
return res;
}
How can improve this algorithm ?
You can do this:
var a = ['a', 'b', 'c', 'd'],
b = [1, 0, 3, 2];
function mySort(array, rules) {
var sorted = [];
for (var i=0; i< rules.length; i++) {
sorted[rules[i]] = array[i];
}
return sorted;
}
mySort(a, b);
> ["b", "a", "d", "c"]
If you convert it to an array of arrays ([[1,'a'],[0,'b'],[3,'c'],[2,'d']]), which shouldn't be difficult, you can then call Javascript's built-in array.sort() method to sort it.
Pure JS solution
var result = b.map(function(idx) {
return a[idx];
});
I would use some library like lodash or underscore
var result = _.map(b, function(idx) {
return a[idx];
});
I would also note it is usually better to run a benchmark on a decently large data set. There is overhead when running a benchmark and as the data gets larger the less this overhead effects the results.
