heap

问题 e.g. A permutation algorithm for {&, *, %} to be placed in 8 positions: &&&&&&&&& &&&&&&&&* &&&&&&&&% &&&&&&&*% &&&&&&&** ... Heap's permutation algorithm I saw on the Internet works just for those who the number of characters are equal to the number of positions, And those who can work with unequal number of characters and number of positions, Only work with integers, Not characters. I also have to say I haven't reached any working algorithm up to now, As I don't know anything about

问题 e.g. A permutation algorithm for {&, *, %} to be placed in 8 positions: &&&&&&&&& &&&&&&&&* &&&&&&&&% &&&&&&&*% &&&&&&&** ... Heap's permutation algorithm I saw on the Internet works just for those who the number of characters are equal to the number of positions, And those who can work with unequal number of characters and number of positions, Only work with integers, Not characters. I also have to say I haven't reached any working algorithm up to now, As I don't know anything about

问题 e.g. A permutation algorithm for {&, *, %} to be placed in 8 positions: &&&&&&&&& &&&&&&&&* &&&&&&&&% &&&&&&&*% &&&&&&&** ... Heap's permutation algorithm I saw on the Internet works just for those who the number of characters are equal to the number of positions, And those who can work with unequal number of characters and number of positions, Only work with integers, Not characters. I also have to say I haven't reached any working algorithm up to now, As I don't know anything about

问题 I have a binary that contains a list of short strings which is loaded on startup and stored in memory as a map from string to protobuf (that contains the string..). (Not ideal, but hard to change that design due to legacy issues) Recently that list has grown from ~2M to ~20M entries causing it to fail when constructing the map. First I got OutOfMemoryError: Java heap space . When I increased the heap size using the xms and xmx we ran into GC overhead limit exceeded . Runs on a Linux 64-bit

问题 I have a binary that contains a list of short strings which is loaded on startup and stored in memory as a map from string to protobuf (that contains the string..). (Not ideal, but hard to change that design due to legacy issues) Recently that list has grown from ~2M to ~20M entries causing it to fail when constructing the map. First I got OutOfMemoryError: Java heap space . When I increased the heap size using the xms and xmx we ran into GC overhead limit exceeded . Runs on a Linux 64-bit

问题 I understand the difference between new gen / old gen /perm gen, but I don't know what "To Space" and "From Space" are. I am seeing my "From Space" hitting 99.8% used while the "To Space" always seems to stay at 0% used. 回答1: Two regions in the garbage-collection algorithm that is used in the VM. Java specifics are found here: How Garbage Collection works in Java And a general explanation about "from space" and "to space": WP The most straightforward approach is the semi-space collector,

问题 I understand the difference between new gen / old gen /perm gen, but I don't know what "To Space" and "From Space" are. I am seeing my "From Space" hitting 99.8% used while the "To Space" always seems to stay at 0% used. 回答1: Two regions in the garbage-collection algorithm that is used in the VM. Java specifics are found here: How Garbage Collection works in Java And a general explanation about "from space" and "to space": WP The most straightforward approach is the semi-space collector,

问题 I recently read Bernard Chazelle's paper "The Soft Heap, An Approximate Priority Queue with Optimal Error Rate by Bernard Chazelle" (http://www.link.cs.cmu.edu/15859-f07/papers/chazelle-soft-heap.pdf) The paper talks a lot about "corruption." What is corruption, how do elements get corrupted, and how does it help you? I have spent a lot of time reading through the paper and Googling and this still doesn't make sense. 回答1: In most research papers on priority queues, each element in the queue

问题 I recently read Bernard Chazelle's paper "The Soft Heap, An Approximate Priority Queue with Optimal Error Rate by Bernard Chazelle" (http://www.link.cs.cmu.edu/15859-f07/papers/chazelle-soft-heap.pdf) The paper talks a lot about "corruption." What is corruption, how do elements get corrupted, and how does it help you? I have spent a lot of time reading through the paper and Googling and this still doesn't make sense. 回答1: In most research papers on priority queues, each element in the queue

问题 I recently read Bernard Chazelle's paper "The Soft Heap, An Approximate Priority Queue with Optimal Error Rate by Bernard Chazelle" (http://www.link.cs.cmu.edu/15859-f07/papers/chazelle-soft-heap.pdf) The paper talks a lot about "corruption." What is corruption, how do elements get corrupted, and how does it help you? I have spent a lot of time reading through the paper and Googling and this still doesn't make sense. 回答1: In most research papers on priority queues, each element in the queue