Created
February 15, 2013 17:31
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Quick sort
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var sort = function(arr, left, right){ | |
if (right <= left) return; | |
// 取中間值作為 pivot | |
var pivotIndex = parseInt((left + right) / 2), | |
pivot = arr[pivotIndex]; | |
// pivot 移至最右方 | |
swap(arr, pivotIndex, right); | |
// 最左方元素設定為索引 | |
var swapIndex = left; | |
// 小於基準的元素搬至索引左方 | |
for (var i = left; i < right; i++){ | |
if (arr[i] <= pivot){ | |
swap(arr, i, swapIndex++); | |
} | |
} | |
// 索引與 pivot 交換位置 | |
swap(arr, swapIndex, right); | |
sort(arr, left, swapIndex - 1); | |
sort(arr, swapIndex + 1, right); | |
return arr; | |
}; | |
var swap = function(arr, a, b){ | |
var tmp = arr[a]; | |
arr[a] = arr[b]; | |
arr[b] = tmp; | |
}; |
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