bottomupsort算法比较次数 讨论排序算法的比较次数能帮我们更好理解效率差异。bottom-upsort通常指自底向上的归并排序，这里重点分析它的比较行为。归并排序通过拆分与合并完成排序。自底向上版本直接从单个元素开始两两合并，逐步扩大合并块大小。假设数组长度为n，每轮合并的子数组长度从1开始翻倍，直到覆盖整个数组。比...
{ cout << "经过Bottomupsort后:"; for(int i = 1; i <=n; i ++) { cout << A[i] << " "; } cout << endl; } void Merge(int a[], int p, int q, int r) { int b[N]; int s = p, t = q+1, k = p; while(s <= q && t <= r) { if(a[s] <= a[t]) ...
mergesort(A, temp, 0, N - 1); printf("Modified array: "); printArray(A); return 0; } 下载 运行代码 Java Python 迭代归并排序的最坏情况时间复杂度与递归的实现保持一致,即 O(n.log(n)) 对于包含的输入 n 项目。但是,它节省了调用堆栈所需的辅助空间。 另见: 外部合并排序算法 参考: http:...
}voidPrint() { cout<<"经过Bottomupsort后:";for(inti =1; i <=n; i ++) { cout<< A[i] <<""; } cout<<endl; }voidMerge(inta[],intp,intq,intr) {intb[N];ints = p, t = q+1, k =p;while(s <= q && t <=r) {if(a[s] <=a[t]) { b[k++] = a[s++]; }els...
Bottom-up mergesort--a detailed analysis. Algo- rithmica, 14(4):340-354, 1995. doi:10.1007/BF01294131.Wolfgang Panny and Helmut Prodinger, "Bottom-up Mergesort - a Detailed Analysis", Algorithmica 14(4): 340-354 (1995)W. Panny, H. Prodinger, Bottom-up mergesort--a detailed analysis...
Bottom-Up-Heapsort is a variant of Heapsort. Its worst-case complexity for the number of comparisons is known to be bounded from above by 3/2n logn+0(n), wheren is the number of elements to be sorted. There is also an example of a heap which needs 5/4n logn-0(n log logn) com...
如果归并结束时,flag 的值为 false,表示最后一次归并是将 seq 归并到 aux 上,最终 aux 是有序的,seq 是无序的。只要将 aux 上的所有元素复制到 seq 上, 序列 seq 就有序了。 defmerge_sortBU(seq):defone_way_merge(seq1,l,m,h,seq2):i=lj=m...
双程归并涉及辅助序列aux，将两个有序小片段合并，形成一个更大有序序列。这一过程通过两次复制完成。实现双程归并操作后，自底向上的归并排序算法通过多次size-size归并，逐步构建有序序列。size从1递增，每次将两个相邻且各自有序的小片段合并。注意到，在双程归并中，真正有效的是将序列小片段合并到...
Though the behaviors of mergesort algorithms are basically known, the periodicity phenomena encountered in their analyses are not easy to deal with. In this paper closed-form expressions for the necessary number of comparisons are derived for the bottom-up algorithm, which adequately describe its per...
Bottom-Up-Heapsort is a variant of Heapsort. Its worst case complexity for the number of comparisons is known to be bounded from above by 3/2 n log n+O(n) , where n is the number of elements to be sorted. There is also an example of a heap which needs 5/2 n log nO(n log...