JavaScriptArray.Sort实现?JavaScript是哪种算法Array#sort()功能使用?我知道它可以使用各种参数和函数来执行不同类型的排序,我只对普通排序所使用的算法感兴趣。
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摇曳的蔷薇
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var QuickSort = function QuickSort(a, from, to) { var third_index = 0; while (true) { // Insertion sort is faster for short arrays. if (to - from <= 10) { InsertionSort(a, from, to); return; } if (to - from > 1000) { third_index = GetThirdIndex(a, from, to); } else { third_index = from + ((to - from) >> 1); } // Find a pivot as the median of first, last and middle element. var v0 = a[from]; var v1 = a[to - 1]; var v2 = a[third_index]; var c01 = comparefn(v0, v1); if (c01 > 0) { // v1 < v0, so swap them. var tmp = v0; v0 = v1; v1 = tmp; } // v0 <= v1. var c02 = comparefn(v0, v2); if (c02 >= 0) { // v2 <= v0 <= v1. var tmp = v0; v0 = v2; v2 = v1; v1 = tmp; } else { // v0 <= v1 && v0 < v2 var c12 = comparefn(v1, v2); if (c12 > 0) { // v0 <= v2 < v1 var tmp = v1; v1 = v2; v2 = tmp; } } // v0 <= v1 <= v2 a[from] = v0; a[to - 1] = v2; var pivot = v1; var low_end = from + 1; // Upper bound of elements lower than pivot. var high_start = to - 1; // Lower bound of elements greater than pivot. a[third_index] = a[low_end]; a[low_end] = pivot; // From low_end to i are elements equal to pivot. // From i to high_start are elements that haven't been compared yet. partition: for (var i = low_end + 1; i < high_start; i++) { var element = a[i]; var order = comparefn(element, pivot); if (order < 0) { a[i] = a[low_end]; a[low_end] = element; low_end++; } else if (order > 0) { do { high_start--; if (high_start == i) break partition; var top_elem = a[high_start]; order = comparefn(top_elem, pivot); } while (order > 0); a[i] = a[high_start]; a[high_start] = element; if (order < 0) { element = a[i]; a[i] = a[low_end]; a[low_end] = element; low_end++; } } } if (to - high_start < low_end - from) { QuickSort(a, high_start, to); to = low_end; } else { QuickSort(a, from, low_end); from = high_start; } } };
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