Created
January 14, 2012 12:37
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Heapsort example in javascript (i think)
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var list = [9,1,7,3,4,2,8,0,5,6]; | |
function chunk(list) { | |
var chunks = []; | |
for(var i=0; i<list.length; i++) { | |
if(list.length % 2 == 1 && i+1 == list.length) { | |
chunks.push(list[i]); | |
} else { | |
if(i % 2 == 0) { | |
chunks.push(Math.max(list[i], list[i+1])); | |
} | |
} | |
} | |
return chunks; | |
} | |
function bubble(list) { | |
var remainder = chunk(list), | |
heap = [list]; | |
heap.push(remainder); | |
while(remainder.length != 1) { | |
remainder = chunk(remainder); | |
heap.push(remainder); | |
} | |
return heap; | |
} | |
function getTopIndex(thing) { | |
var currentIndex = 0, | |
value = thing[thing.length-1][0], | |
i = thing.length -2; | |
while(i != -1) { | |
if(!thing[i].length % 2 && currentIndex > 0) { | |
currentIndex--; | |
} | |
if(thing[i][currentIndex + 1] == value) { | |
currentIndex++; | |
currentIndex = i ? currentIndex << 1 : currentIndex; | |
} else if(currentIndex) { | |
currentIndex = i ? currentIndex << 1 : currentIndex; | |
} | |
i--; | |
} | |
return currentIndex; | |
} | |
function heapSort(list) { | |
var sortedList = [], | |
listCopy = list, | |
heap = [] | |
targetLength = list.length; | |
while(sortedList.length != targetLength) { | |
heap = bubble(listCopy); | |
sortedList.push(heap[heap.length-1][0]); | |
listCopy.splice(getTopIndex(heap), 1); | |
} | |
return sortedList; | |
} | |
console.log(heapSort(list)); |
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Thanks for sharing. One trivial issue: in function
heapSort
: