Data commit

Task/Sorting-algorithms-Permutation-sort/ActionScript/sorting-algorithms-permutation-sort.as

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+//recursively builds the permutations of permutable, appended to front, and returns the first sorted permutation it encounters
+function permutations(front:Array, permutable:Array):Array {
+	//If permutable has length 1, there is only one possible permutation. Check whether it's sorted
+	if (permutable.length==1)
+		return isSorted(front.concat(permutable));
+	else
+		//There are multiple possible permutations. Generate them.
+		var i:uint=0,tmp:Array=null;
+		do
+		{
+			tmp=permutations(front.concat([permutable[i]]),remove(permutable,i));
+			i++;
+		}while (i< permutable.length && tmp == null);
+		//If tmp != null, it contains the sorted permutation. If it does not contain the sorted permutation, return null. Either way, return tmp.
+		return tmp;
+}
+//returns the array if it's sorted, or null otherwise
+function isSorted(data:Array):Array {
+	for (var i:uint = 1; i < data.length; i++)
+		if (data[i]<data[i-1])
+			return null;
+	return data;
+}
+//returns a copy of array with the i'th element removed
+function remove(array:Array, i:uint):Array {
+	return array.filter(function(item,index,array){return(index !=i)}) ;
+}
+//wrapper around the permutation function to provide a more logical interface
+function permutationSort(array:Array):Array {
+	return permutations([],array);
+}