查找

二分查找
适用于有序表查找, 包括二叉排序树

int BinarySearch(int *array, int aSize, int key) 
{ 
    if ( array == NULL || aSize == 0 ) 
        return -1; 
    int low = 0; 
    int high = aSize - 1; 
    int mid = 0; 

    while ( low <= high ) 
    { 
        mid = (low + high )/2; 

        if ( array[mid] < key) 
            low = mid + 1;          
        else if ( array[mid] > key )     
            high = mid - 1; 
        else 
            return mid; 
    } 
    return -1; 
}

散列查找
请看本博客数据结构与算法hash表文章
http://www.jianshu.com/writer#/notebooks/15612823/notes/16627768