heap

问题 I am using SQL Server 2008. I know if a table has no clustered index, then it is called heap, or else the storage model is called clustered index (B-Tree). I want to learn more about what exactly means heap storage, what it looks like and whether it is organized as "heap" data structure (e.g. minimal heap, maximum heap). Any recommended readings? I want to more a bit more internals, but not too deep. :-) thanks in advance, George 回答1: Heap storage has nothing to do with these heaps. Heap just

问题 I have a simple heap defined as a list of lists. I was using heapop from the heapq module to extract the list with the smallest key (which I learnt is implicitly the first element of the inner list). But in the following case, the pop operation seems to be giving unusual results. Can someone explain why? heap=[[0, 0, 0], [inf, 1, 1], [inf, 2, 2], [5, 3, 3], [inf, 4, 4]] heapq.heappop(heap) [0, 0, 0] heapq.heappop(heap) [inf, 1, 1] heapq.heappop(heap) [5, 3, 3] heapq.heappop(heap) [inf, 2, 2]

问题 I have a simple heap defined as a list of lists. I was using heapop from the heapq module to extract the list with the smallest key (which I learnt is implicitly the first element of the inner list). But in the following case, the pop operation seems to be giving unusual results. Can someone explain why? heap=[[0, 0, 0], [inf, 1, 1], [inf, 2, 2], [5, 3, 3], [inf, 4, 4]] heapq.heappop(heap) [0, 0, 0] heapq.heappop(heap) [inf, 1, 1] heapq.heappop(heap) [5, 3, 3] heapq.heappop(heap) [inf, 2, 2]

问题 When configured for mutability, boost::heap::d_ary_heap uses a std::list in addition to the vector that holds the values of the heap nodes. I realize that the handles which are being provided for making the mutable_heap_interface work are in fact iterators of this list, but I'm wondering why such an expensive solution was chosen, and if there's a leaner way to achieve mutability with boost::heap::d_ary_heap . Mutability requires a way to find the index of a node in the heap vector, given the

问题 When configured for mutability, boost::heap::d_ary_heap uses a std::list in addition to the vector that holds the values of the heap nodes. I realize that the handles which are being provided for making the mutable_heap_interface work are in fact iterators of this list, but I'm wondering why such an expensive solution was chosen, and if there's a leaner way to achieve mutability with boost::heap::d_ary_heap . Mutability requires a way to find the index of a node in the heap vector, given the

问题 When configured for mutability, boost::heap::d_ary_heap uses a std::list in addition to the vector that holds the values of the heap nodes. I realize that the handles which are being provided for making the mutable_heap_interface work are in fact iterators of this list, but I'm wondering why such an expensive solution was chosen, and if there's a leaner way to achieve mutability with boost::heap::d_ary_heap . Mutability requires a way to find the index of a node in the heap vector, given the

问题 I'm trying to allocate an array as follows: class foo{ public: void func(){double arr[13][64][64][64];} }; int main() { foo* inst = new foo(); inst->func(); return 0; } I was under the impression from answer such as: Does this type of memory get allocated on the heap or the stack? that the array arr would be placed on the heap (as the instance of the class is on the heap). This doesn't seem to be the case as I get a segmentation fault. If I change a's declaration to: double* arr = new double

问题 I'm trying to allocate an array as follows: class foo{ public: void func(){double arr[13][64][64][64];} }; int main() { foo* inst = new foo(); inst->func(); return 0; } I was under the impression from answer such as: Does this type of memory get allocated on the heap or the stack? that the array arr would be placed on the heap (as the instance of the class is on the heap). This doesn't seem to be the case as I get a segmentation fault. If I change a's declaration to: double* arr = new double

问题 I would like to use ptrace in order to attach my tool to a Linux process, read and write to the heap memory of this process and again detach my tool. Actually, it's not working although there is no error. I can not see any modifications in the heap memory of the process after I run the tool. Anyway, I'm quite not sure if that is possible in general. Currently, my C code looks like this: int res = 0, i = 0; int size = heap_address->end - heap_address->start; char tmp_page[size]; memset(tmp

问题 I would like to use ptrace in order to attach my tool to a Linux process, read and write to the heap memory of this process and again detach my tool. Actually, it's not working although there is no error. I can not see any modifications in the heap memory of the process after I run the tool. Anyway, I'm quite not sure if that is possible in general. Currently, my C code looks like this: int res = 0, i = 0; int size = heap_address->end - heap_address->start; char tmp_page[size]; memset(tmp