O(NlgK)问题优先队列实现文件C语言-优快云博客

本文介绍了一个基于最小堆实现的优先队列的数据结构。该优先队列支持初始化、判断空满状态、插入元素、删除最小元素等操作，并提供了调整堆的操作确保堆的性质。适用于需要高效管理优先级任务的场景。

/* PriorityQueue.c -- 最小堆实现文件 */ #include "PriorityQueue.h" /* 局部函数声明 */ static BOOL percolateUp_P (PriorityNode * const heap, const int position, const int size) ; static BOOL percolateDown_P (PriorityNode * const heap, const int position, const int size) ; /* 接口函数定义 */ BOOL Initialize_P (PriorityQueue * const ppq, const int size) { if (size <= 0) return FALSE ; *ppq = (struct priorityQueue *) malloc (sizeof (struct priorityQueue)) ; if (NULL == *ppq) return FALSE ; (*ppq) -> heap = (PriorityNode *) malloc (sizeof (PriorityNode) * (size + 1)) ; if (NULL == (*ppq) -> heap) { free (*ppq) ; return FALSE ; } (*ppq) -> current = 0 ; (*ppq) -> size = size ; return TRUE ; } BOOL IsEmpty_P (const PriorityQueue * const ppq) { if (0 == (*ppq) -> current) return TRUE ; else return FALSE ; } BOOL IsFull_P (const PriorityQueue * const ppq) { if ((*ppq) -> current == (*ppq) -> size) return TRUE ; else return FALSE ; } BOOL Insert_P (const PriorityQueue * const ppq, const PriorityNode pn) { if (TRUE == IsFull_P (ppq)) return FALSE ; (*ppq) -> heap[++(*ppq) -> current] = pn ; percolateUp_P ((*ppq) -> heap, (*ppq) -> current, (*ppq) -> current) ; return TRUE ; } PriorityNode DeleteMin_P (const PriorityQueue * const ppq) { PriorityNode record ; if (IsEmpty_P (ppq)) return NULL ; record = (*ppq) -> heap[1] ; (*ppq) -> heap[1] = (*ppq) -> heap[(*ppq) -> current--] ; percolateDown_P ((*ppq) -> heap, 1, (*ppq) -> current) ; return record ; } BOOL IncreaseKey_P (const PriorityQueue * const ppq, const int position, const Item delta) { if (position < 1 || position > (*ppq) -> current || delta <= 0) return FALSE ; (*ppq) -> heap[position] -> item += delta ; percolateDown_P ((*ppq) -> heap, position, (*ppq) -> current) ; return TRUE ; } BOOL DecreaseKey_P (const PriorityQueue * const ppq, const int position, const Item delta) { if (position < 1 || position > (*ppq) -> current || delta <= 0) return FALSE ; (*ppq) -> heap[position] -> item -= delta ; percolateUp_P ((*ppq) -> heap, position, (*ppq) -> current) ; return TRUE ; } void Release_P (const PriorityQueue * const ppq) { free ((*ppq) -> heap) ; free (*ppq) ; } /* 局部函数定义 */ static BOOL percolateUp_P (PriorityNode * const heap, const int position, const int size) { PriorityNode temp ; int i ; if (position < 1 || position > size) return FALSE ; temp = heap[position] ; for (i = position; PARENT (i) >= 1 && heap[PARENT (i)] -> item > temp -> item; i = PARENT (i)) heap[i] = heap[PARENT (i)] ; heap[i] = temp ; return TRUE ; } static BOOL percolateDown_P (PriorityNode * const heap, const int position, const int size) { PriorityNode temp ; int i, child ; if (position < 1 || position > size) return FALSE ; temp = heap[position] ; for (i = position; LEFT (i) <= size; i = child) { child = LEFT (i) ; if (child != size && heap[child] -> item > heap[child + 1] -> item) child = RIGHT (i) ; if (temp -> item > heap[child] -> item) heap[i] = heap[child] ; else break ; } heap[i] = temp ; return TRUE ; }