题目：
Insert a sequence of given numbers into an initially empty min-heap H. Then for any given index i, you are supposed to print the path from H[i] to the root.
Input Specification:
Each input file contains one test case. For each case, the first line gives two positive integers N and M (<=1000) which are the size of the input sequence, and the number of indices to be checked, respectively. Given in the next line are the N integers in [-10000, 10000] which are supposed to be inserted into an initially empty min-heap. Finally in the last line, M indices are given.
Output Specification:
For each index i in the input, print in one line the numbers visited along the path from H[i] to the root of the heap. The numbers are separated by a space, and there must be no extra space at the end of the line.
Sample Input:
5 3 46 23 26 24 10 5 4 3
Sample Output:
24 23 10 46 23 10 26 10
分析：主要是考查最小堆的建立。
代码：
typedef struct heapNode { int elements[1000]; int size; int capacity; } MinHeapNode; MinHeapNode *createHeap(int maxSize) { MinHeapNode *heap = (MinHeapNode *)malloc(sizeof(MinHeapNode)); heap->size = 0; heap->capacity = maxSize; heap->elements[0] = -10001; // 哨兵 return heap; } void insertToMinHeap(MinHeapNode *heap, int item) { if (heap->size == heap->capacity) { return; // 堆已满，无法插入 } int i = ++heap->size; for (; heap->elements[i / 2] > item; i /= 2) { heap->elements[i] = heap->elements[i / 2]; } heap->elements[i] = item; } int main() { // 接受输入 int itemNum, indexNum; scanf("%d %d", &itemNum, &indexNum); MinHeapNode *heap = createHeap(itemNum); for (int i = 0; i < itemNum; i++) { int item; scanf("%d", &item); insertToMinHeap(heap, item); } int a[indexNum]; for (int i = 0; i < indexNum; i++) { int index; scanf("%d", &index); a[i] = index; } for (int i = 0; i < indexNum; i++) { int searchIndex = a[i]; int flag = 1; while (searchIndex > 0) { if (flag) { printf("%d", heap->elements[searchIndex]); flag = 0; } else { printf(" %d", heap->elements[searchIndex]); } searchIndex /= 2; } printf("\n"); } }
运行结果：
原文：http://www.cnblogs.com/liufeng24/p/4395780.html