1 #include <stdio.h>
  2 #include <assert.h>
  3
  4 void swap_value( int heap[], int lhs, int rhs )
  5 {
  6     int tmp = heap[lhs];
  7     heap[lhs] = heap[rhs];
  8     heap[rhs] = tmp;
  9 }
 10
 11 /** @*current_size: 表示heap中已经存在的元素个数。
 12  ** @heap_size：表示heap的最大容量是多少
 13  */
 14 void insert_to_heap( int heap[], int *current_size,
 15                      int heap_size, const int value )
 16 {
 17     int child = *current_size;
 18     int parent = 0;
 19
 20     assert( *current_size < heap_size );
 21     heap[child++] = value;
 22     parent = child / 2;
 23     while ( parent >= 0 )
 24     {
 25         if ( heap[child] > heap[parent] )
 26         {
 27             swap_value( heap, child, parent );
 28             child = parent;
 29             parent /= 2;
 30         }
 31         else
 32             parent = -1;
 33     }
 34     *current_size += 1;
 35 }
 36
 37 int remove_max_from_heap( int heap[], int *current_size )
 38 {
 39     int result = 0;
 40     int child = 0;
 41     int parent = 0;
 42
 43     if ( *current_size == 0 )
 44     {
 45         printf( "remove_max_from_heap: the heap is empty.\n" );
 46         return -1;
 47     }
 48
 49     result = heap[0];
 50     swap_value( heap, 0, *current_size - 1 );
 51     --*current_size;
 52     child = 1;
 53     while ( child <= *current_size - 1 )
 54     {
 55         if ( child < *current_size - 1
 56             && heap[child] < heap[child + 1] )
 57         {
 58             child += 1;
 59         }
 60
 61         if ( heap[child] > heap[parent] )
 62         {
 63             swap_value( heap, child, parent );
 64             parent = child;
 65             child *= 2;
 66         }
 67         else
 68         {
 69             child = *current_size;
 70         }
 71     }
 72
 73     return result;
 74 }
 75
 76 void build_heap( int heap[], int current_size )
 77 {
 78     int start = 0;
 79
 80     while ( start < current_size - 1 )
 81     {
 82         insert_to_heap( heap, &start, start + 1, heap[start] );
 83     }
 84 }
 85
 86 void heap_sort( int heap[], int current_size )
 87 {
 88     int i = current_size - 1;
 89     int j = current_size;
 90
 91     build_heap( heap, current_size );
 92     while ( j )
 93     {
 94         int data = remove_max_from_heap( heap, &j );
 95         heap[i] = data;
 96         --i;
 97     }
 98 }
 99
100 int main()
101 {
102     int heap[] = { 78, 58, 87, 62, 92, 332, 55, 40, 75, 146 };
103     int heap_size = sizeof(heap) / sizeof(int);
104     int i = 0;
105
106     heap_sort( heap, heap_size );
107     while ( i < heap_size )
108     {
109         printf( "%d ", heap[i++] );
110     }
111
112
113     return 0;
114 }