标签:style blog color io 使用 ar for 2014 art
1 //goal: heap sort 2 //time: 9/7/2014 3 //author: zrss 4 //reference: introduction to algorithms 5 6 #include <cstdio> 7 #include <cstring> 8 9 #define MAX_DATA 10 10 11 class MaxHeap { 12 public: 13 MaxHeap(int *data, int size); 14 15 void heap_sort(void); //堆排序,升序 16 17 void output(void); 18 19 private: 20 void max_heapify(int i, int size); //使以i为根的子树成为最大堆,假设i左右子树均为最大堆 21 void build_maxheap(int size); //自底向上使用max_heapify调整,建堆 22 23 private: 24 int size; 25 int array[MAX_DATA]; //从下标0开始存储 26 }; 27 28 MaxHeap::MaxHeap(int *data, int size):size(size) { 29 if (size > MAX_DATA) 30 return; 31 32 memcpy(array, data, sizeof(int) * size); 33 } 34 35 void MaxHeap::max_heapify(int i, int size) { 36 bool check = true; 37 38 while (check) { 39 int l = (i << 1) + 1; 40 int r = l + 1; 41 42 int largest = i; 43 44 //与子节点比较 45 if (l < size && array[l] > array[i]) 46 largest = l; 47 48 if (r < size && array[r] > array[largest]) 49 largest = r; 50 51 if (largest != i) { 52 int temp = array[largest]; 53 array[largest] = array[i]; 54 array[i] = temp; 55 56 i = largest; //从被交换的子节点位置继续调整 57 } 58 else 59 check = false; //父节点不小于子节点,满足最大堆性质,停止调整 60 } 61 } 62 63 void MaxHeap::build_maxheap(int size) { 64 int leaf_start_index = size >> 1; //后续元素为叶子节点 65 66 //从第一个父节点开始调整 67 for (int i = leaf_start_index - 1; i >= 0; --i) 68 max_heapify(i, size); 69 } 70 71 void MaxHeap::heap_sort(void) { 72 int cur_size = size; 73 74 while (cur_size > 1) { 75 //调整成堆 76 build_maxheap(cur_size); 77 78 //将最大值与堆末尾元素交换 79 int temp = array[cur_size - 1]; 80 array[cur_size - 1] = array[0]; 81 array[0] = temp; 82 83 --cur_size; 84 } 85 } 86 87 void MaxHeap::output(void) { 88 for (int i = 0; i < size; ++i) 89 printf("%d ", array[i]); 90 }
标签:style blog color io 使用 ar for 2014 art
原文地址:http://www.cnblogs.com/hzhesi/p/3961199.html