STL源码剖析之算法：make_heap

template <class RandomAccessIterator>                                             
inline void make_heap(RandomAccessIterator first, RandomAccessIterator last) {    
    __make_heap(first, last, value_type(first), distance_type(first));            
} 

template <class RandomAccessIterator, class T, class Distance>                    
void __make_heap(RandomAccessIterator first, RandomAccessIterator last, 
                 T*, Distance*) {                                                 
    if(last - first < 2) return;                                                  
    Distance len = last - first;                                                  
    Distance parent = (len - 2)/2;                                                
                                                                                  
    while(true) {                                                                 
        __adjust_heap(first, parent, len, T(*(first + parent)));                  
        if(parent == 0) return;                                                   
        --parent;                                                                 
    }                                                                             
}                                                                   

注：__adjust_heap源码请见http://zxn990.blog.51cto.com/4253193/1165524