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我正在使用 boost 库编写图挖掘代码,我想使用 vf2_sub_graph_iso
函数,一般来说,如果 vf2_sub_graph_iso
返回 true
图-子图同构存在,否则为 false
,但在我的例子中,我想让它返回 true
只有当图完全相同(结构和标签)时,如官方文档中提到:EdgeEquivalencePredicate
和VertexEquivalencePredicate
谓词用于测试边和顶点是否等价。
这是图形文件:3test.txt这是我的部分代码:
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/vf2_sub_graph_iso.hpp>
#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/config.hpp>
#include <boost/graph/isomorphism.hpp>
#include <boost/graph/graph_utility.hpp>
#include <fstream>
#include <iostream>
#include <vector>
//for mmap:
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
using namespace std;
using namespace boost;
//==========STRUCTURES==========
// vertex
struct VertexProperties {
int id;
int label;
VertexProperties(unsigned i = 0, unsigned l = 0) : id(i), label(l) {}
};
// edge
struct EdgeProperties {
unsigned label;
EdgeProperties(unsigned l = 0) :label(l) {}
};
// Graph
struct GraphProperties {
unsigned id;
unsigned label;
GraphProperties(unsigned i = 0, unsigned l = 0) : id(i), label(l) {}
};
// adjency list
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties,
GraphProperties> Graph;
// descriptors
typedef boost::graph_traits<Graph>::vertex_descriptor vertex_t;
typedef std::pair<boost::graph_traits<Graph>::edge_descriptor, bool> edge_t;
// iterators
typedef graph_traits<Graph>::vertex_iterator vertex_iter;
typedef graph_traits<Graph>::edge_iterator edge_iter;
typedef std::pair<edge_iter, edge_iter> edge_pair;
//*********global variables*************
vector<Graph> dataG;
//=================callback used fro subgraph_iso=================================================================
// Default print_callback
template <typename Graph1,typename Graph2>
struct my_callback {
my_callback(const Graph1& graph1, const Graph2& graph2)
: graph1_(graph1), graph2_(graph2) {}
template <typename CorrespondenceMap1To2,
typename CorrespondenceMap2To1>
bool operator()(CorrespondenceMap1To2 f, CorrespondenceMap2To1) const {
return true;
}
private:
const Graph1& graph1_;
const Graph2& graph2_;
};
//==========handle_error==========
void handle_error(const char *msg) {
perror(msg);
exit(255);
}
//============READ ALL THE FILE AND RETURN A STRING===================
const char *readfromfile(const char *fname, size_t &length) {
int fd = open(fname, O_RDONLY);
if (fd == -1)
handle_error("open");
// obtain file size
struct stat sb;
if (fstat(fd, &sb) == -1)
handle_error("fstat");
length = sb.st_size;
const char *addr = static_cast<const char *>(mmap(NULL, length, PROT_READ, MAP_PRIVATE, fd, 0u));
if (addr == MAP_FAILED)
handle_error("mmap");
// TODO close fd at some point in time, call munmap(...)
return addr;
}
//==========SPLIT THE STRING BY NEWLINE (\n) ==========
vector<string> splitstringtolines(string const& str) {
std::vector<string> split_vector;
split(split_vector, str, is_any_of("\n"));
return split_vector;
}
//============Get a string starting from pos============
string getpos(int const& pos, string const& yy) {
size_t i = pos;
string str;
for (; ((yy[i] != ' ') && (i < yy.length())); i++) {str += yy[i];}
return str;
}
//==================read string vector and return graphs vector===================
std::vector<Graph> creategraphs(std::vector<string> const& fichlines) {
for (string yy : fichlines) {
switch (yy[0]) {
case 't': {
string str2 = getpos(4, yy);
unsigned gid = atoi(str2.c_str());
dataG.emplace_back(GraphProperties(gid, gid));
} break;
case 'v': {
assert(!dataG.empty()); // assert will terminate the program if its argument turns out to be false
// cout<<yy<<endl;
int vId, vLabel;
string vvv = getpos(2, yy);
vId = atoi(vvv.c_str());
string vvvv = getpos((int)vvv.length() + 3, yy);
// cout<<vvvv<<endl;
vLabel = atoi(vvvv.c_str());
boost::add_vertex(VertexProperties(vId, vLabel), dataG.back());
}
break;
case 'e': { // cout<<yy<<endl;
assert(!dataG.empty()); // assert will terminate the program if its argument turns out to be false
int fromId, toId, eLabel;
string eee = getpos(2, yy);
// cout<<eee<<endl;
fromId = atoi(eee.c_str());
string eee2 = getpos((int)eee.length() + 3, yy);
// cout<<eee2<<endl;
toId = atoi(eee2.c_str());
int c = (int)eee.length() + (int)eee2.length() + 4;
// cout<<c<<endl;
string eee3 = getpos(c, yy);
// cout<<eee3<<endl;
eLabel = atoi(eee3.c_str());
for (size_t i = 0; i < num_vertices(dataG.back()); ++i) // size_t vertice number in the graph
{
if(dataG.back()[i].id==fromId) fromId=i;
else if(dataG.back()[i].id==toId) toId=i;
}
boost::add_edge(fromId, toId, EdgeProperties(eLabel), dataG.back());
} break;
}
}
return dataG;
}
//==============================M A I N P R O G R A M =======================================
int main()
{
size_t length;
std::vector<Graph> dataG =creategraphs(splitstringtolines(readfromfile("3test.txt", length)));
my_callback<Graph, Graph> my_callback(dataG[0], dataG[3]);
cout<<"equal(dataG[0], dataG[3],my_callback)="<<vf2_sub_graph_iso(dataG[0], dataG[3],my_callback)<<endl;
}
对于我的情况,如何在 my_callback
函数中使用属性映射实现等价?
这是一个简单的图形文件,只有 2 个图形:
t # 0
v 0 35
v 1 47
v 2 15
v 3 14
v 4 86
e 0 1 10
e 1 2 77
e 1 3 17
e 4 2 43
t # 1
v 0 35
v 1 47
v 2 15
v 3 14
v 4 86
e 0 1 10
e 1 2 7
e 1 3 17
e 4 2 4
这些图具有相同的结构但标签不同,因此此代码必须返回 false 而不是 true:
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/vf2_sub_graph_iso.hpp>
#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/config.hpp>
#include <boost/graph/isomorphism.hpp>
#include <boost/graph/graph_utility.hpp>
#include <boost/tuple/tuple_comparison.hpp>
#include <fstream>
#include <iostream>
#include <vector>
//for mmap:
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
using namespace boost;
//==========STRUCTURES==========
// vertex
struct VertexProperties {
int id;
int label;
VertexProperties(unsigned i = 0, unsigned l = 0) : id(i), label(l) {}
bool operator==(VertexProperties const& other) const {
return tie(id, label) == tie(other.id, other.label);
}
};
// edge
struct EdgeProperties {
unsigned label;
EdgeProperties(unsigned l = 0) :label(l) {}
bool operator==(EdgeProperties const& other) const {
return tie(label) == tie(other.label);
}
};
// Graph
struct GraphProperties {
unsigned id;
unsigned label;
GraphProperties(unsigned i = 0, unsigned l = 0) : id(i), label(l) {}
};
// adjency list
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties,
GraphProperties> Graph;
// descriptors
typedef boost::graph_traits<Graph>::vertex_descriptor vertex_t;
typedef std::pair<boost::graph_traits<Graph>::edge_descriptor, bool> edge_t;
// iterators
typedef graph_traits<Graph>::vertex_iterator vertex_iter;
typedef graph_traits<Graph>::edge_iterator edge_iter;
typedef std::pair<edge_iter, edge_iter> edge_pair;
//*********global variables*************
std::vector<Graph> dataG;
//=================callback used fro subgraph_iso=================================================================
// Default print_callback
template <typename Graph1,typename Graph2>
struct my_callback {
my_callback(const Graph1& graph1, const Graph2& graph2)
: graph1_(graph1), graph2_(graph2) {}
template <typename CorrespondenceMap1To2,
typename CorrespondenceMap2To1>
bool operator()(CorrespondenceMap1To2 /*f*/, CorrespondenceMap2To1) const {
return true;
}
private:
const Graph1& graph1_;
const Graph2& graph2_;
};
//==========handle_error==========
void handle_error(const char *msg) {
perror(msg);
exit(255);
}
//============READ ALL THE FILE AND RETURN A STRING===================
const char *readfromfile(const char *fname, size_t &length) {
int fd = open(fname, O_RDONLY);
if (fd == -1)
handle_error("open");
// obtain file size
struct stat sb;
if (fstat(fd, &sb) == -1)
handle_error("fstat");
length = sb.st_size;
const char *addr = static_cast<const char *>(mmap(NULL, length, PROT_READ, MAP_PRIVATE, fd, 0u));
if (addr == MAP_FAILED)
handle_error("mmap");
// TODO close fd at some point in time, call munmap(...)
return addr;
}
//==========SPLIT THE STRING BY NEWLINE (\n) ==========
std::vector<std::string> splitstringtolines(std::string const& str) {
std::vector<std::string> split_vector;
split(split_vector, str, is_any_of("\n"));
return split_vector;
}
//============Get a string starting from pos============
std::string getpos(int const& pos, std::string const& yy) {
size_t i = pos;
std::string str;
for (; ((yy[i] != ' ') && (i < yy.length())); i++) {str += yy[i];}
return str;
}
//==================read string vector and return graphs vector===================
std::vector<Graph> creategraphs(std::vector<std::string> const& fichlines) {
for (std::string yy : fichlines) {
switch (yy[0]) {
case 't': {
std::string str2 = getpos(4, yy);
unsigned gid = atoi(str2.c_str());
dataG.emplace_back(GraphProperties(gid, gid));
} break;
case 'v': {
assert(!dataG.empty()); // assert will terminate the program if its argument turns out to be false
// std::cout<<yy<<std::endl;
int vId, vLabel;
std::string vvv = getpos(2, yy);
vId = atoi(vvv.c_str());
std::string vvvv = getpos((int)vvv.length() + 3, yy);
// std::cout<<vvvv<<std::endl;
vLabel = atoi(vvvv.c_str());
boost::add_vertex(VertexProperties(vId, vLabel), dataG.back());
}
break;
case 'e': { // std::cout<<yy<<std::endl;
assert(!dataG.empty()); // assert will terminate the program if its argument turns out to be false
int fromId, toId, eLabel;
std::string eee = getpos(2, yy);
// std::cout<<eee<<std::endl;
fromId = atoi(eee.c_str());
std::string eee2 = getpos((int)eee.length() + 3, yy);
// std::cout<<eee2<<std::endl;
toId = atoi(eee2.c_str());
int c = (int)eee.length() + (int)eee2.length() + 4;
// std::cout<<c<<std::endl;
std::string eee3 = getpos(c, yy);
// std::cout<<eee3<<std::endl;
eLabel = atoi(eee3.c_str());
for (size_t i = 0; i < num_vertices(dataG.back()); ++i) // size_t vertice number in the graph
{
if(dataG.back()[i].id==fromId) fromId=i;
else if(dataG.back()[i].id==toId) toId=i;
}
boost::add_edge(fromId, toId, EdgeProperties(eLabel), dataG.back());
} break;
}
}
return dataG;
}
template <typename Graph1, typename Graph2>
bool my_bundled_graph_iso(Graph1 const& graph_small, Graph2 const& graph_large) {
auto const vos = boost::copy_range<std::vector<Graph::vertex_descriptor> >(vertices(graph_small));
return vf2_subgraph_iso(graph_small, graph_large, my_callback<Graph, Graph>(graph_small, graph_large), vos,
edges_equivalent (make_property_map_equivalent(boost::get(edge_bundle, graph_small), boost::get(edge_bundle, graph_large))).
vertices_equivalent(make_property_map_equivalent(boost::get(vertex_bundle, graph_small), boost::get(vertex_bundle, graph_large)))
);
}
//==============================M A I N P R O G R A M =======================================
int main() {
size_t length;
std::vector<Graph> dataG = creategraphs(splitstringtolines(readfromfile("2.txt", length)));
std::cout << std::boolalpha << my_bundled_graph_iso(dataG[0], dataG[1]) << std::endl;
}
我没有在问题和小先例示例中提到顶点可以相同,即使 id 不相同(在不同的图中)。
最佳答案
好的,让我们剖析文档。
为了传递 EdgeEquivalencePredicate
的非默认实现和 VertexEquivalencePredicate
你需要 second overload :
bool vf2_subgraph_iso(const GraphSmall& graph_small,
const GraphLarge& graph_large,
SubGraphIsoMapCallback user_callback,
const VertexOrderSmall& vertex_order_small,
const bgl_named_params<Param, Tag, Rest>& params)
这意味着您至少需要一个参数来匹配vertex_order_small
和 params
.让我们做最少的工作,只供应vertex_order_small
第一:
The ordered vertices of the smaller (first) graph graph_small. During the matching process the vertices are examined in the order given by
vertex_order_small
. TypeVertexOrderSmall
must be a model ofContainerConcept
with value typegraph_traits<GraphSmall>::vertex_descriptor
.Default The vertices are ordered by multiplicity of in/out degrees.
让我们以默认顺序传递一个顶点描述符 vector :
auto const& graph_small = dataG[0];
auto const& graph_large = dataG[3];
auto vos = boost::copy_range<std::vector<Graph::vertex_descriptor> >(vertices(graph_small));
bool iso = vf2_graph_iso(graph_small, graph_large, my_callback, vos, no_named_parameters());
下一步,您添加命名参数,例如:[¹]
bool iso = vf2_graph_iso(graph_small, graph_large, my_callback, vos,
edges_equivalent ([&graph_small, &graph_large](Graph::edge_descriptor small_ed, Graph::edge_descriptor large_ed) {
return graph_small[small_ed] == graph_large[large_ed];
}).
vertices_equivalent([&graph_small, &graph_large](Graph::vertex_descriptor small_vd, Graph::vertex_descriptor large_vd) {
return graph_small[small_vd] == graph_large[large_vd];
})
);
作为最后的topping使用 make_property_map_equivalent
documented here :
bool iso = vf2_graph_iso(graph_small, graph_large, my_callback, vos,
edges_equivalent (make_property_map_equivalent(boost::get(edge_bundle, graph_small), boost::get(edge_bundle, graph_large))).
vertices_equivalent(make_property_map_equivalent(boost::get(vertex_bundle, graph_small), boost::get(vertex_bundle, graph_large)))
);
查看所有三个步骤 Live On Coliru
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/vf2_sub_graph_iso.hpp>
#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/config.hpp>
#include <boost/graph/isomorphism.hpp>
#include <boost/graph/graph_utility.hpp>
#include <boost/tuple/tuple_comparison.hpp>
#include <fstream>
#include <iostream>
#include <vector>
//for mmap:
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
using namespace boost;
//==========STRUCTURES==========
// vertex
struct VertexProperties {
int id;
int label;
VertexProperties(unsigned i = 0, unsigned l = 0) : id(i), label(l) {}
bool operator==(VertexProperties const& other) const {
return tie(id, label) == tie(other.id, other.label);
}
};
// edge
struct EdgeProperties {
unsigned label;
EdgeProperties(unsigned l = 0) :label(l) {}
bool operator==(EdgeProperties const& other) const {
return tie(label) == tie(other.label);
}
};
// Graph
struct GraphProperties {
unsigned id;
unsigned label;
GraphProperties(unsigned i = 0, unsigned l = 0) : id(i), label(l) {}
};
// adjency list
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties,
GraphProperties> Graph;
// descriptors
typedef boost::graph_traits<Graph>::vertex_descriptor vertex_t;
typedef std::pair<boost::graph_traits<Graph>::edge_descriptor, bool> edge_t;
// iterators
typedef graph_traits<Graph>::vertex_iterator vertex_iter;
typedef graph_traits<Graph>::edge_iterator edge_iter;
typedef std::pair<edge_iter, edge_iter> edge_pair;
//*********global variables*************
std::vector<Graph> dataG;
//=================callback used fro subgraph_iso=================================================================
// Default print_callback
template <typename Graph1,typename Graph2>
struct my_callback {
my_callback(const Graph1& graph1, const Graph2& graph2)
: graph1_(graph1), graph2_(graph2) {}
template <typename CorrespondenceMap1To2,
typename CorrespondenceMap2To1>
bool operator()(CorrespondenceMap1To2 /*f*/, CorrespondenceMap2To1) const {
return true;
}
private:
const Graph1& graph1_;
const Graph2& graph2_;
};
//==========handle_error==========
void handle_error(const char *msg) {
perror(msg);
exit(255);
}
//============READ ALL THE FILE AND RETURN A STRING===================
const char *readfromfile(const char *fname, size_t &length) {
int fd = open(fname, O_RDONLY);
if (fd == -1)
handle_error("open");
// obtain file size
struct stat sb;
if (fstat(fd, &sb) == -1)
handle_error("fstat");
length = sb.st_size;
const char *addr = static_cast<const char *>(mmap(NULL, length, PROT_READ, MAP_PRIVATE, fd, 0u));
if (addr == MAP_FAILED)
handle_error("mmap");
// TODO close fd at some point in time, call munmap(...)
return addr;
}
//==========SPLIT THE STRING BY NEWLINE (\n) ==========
std::vector<std::string> splitstringtolines(std::string const& str) {
std::vector<std::string> split_vector;
split(split_vector, str, is_any_of("\n"));
return split_vector;
}
//============Get a string starting from pos============
std::string getpos(int const& pos, std::string const& yy) {
size_t i = pos;
std::string str;
for (; ((yy[i] != ' ') && (i < yy.length())); i++) {str += yy[i];}
return str;
}
//==================read string vector and return graphs vector===================
std::vector<Graph> creategraphs(std::vector<std::string> const& fichlines) {
for (std::string yy : fichlines) {
switch (yy[0]) {
case 't': {
std::string str2 = getpos(4, yy);
unsigned gid = atoi(str2.c_str());
dataG.emplace_back(GraphProperties(gid, gid));
} break;
case 'v': {
assert(!dataG.empty()); // assert will terminate the program if its argument turns out to be false
// std::cout<<yy<<std::endl;
int vId, vLabel;
std::string vvv = getpos(2, yy);
vId = atoi(vvv.c_str());
std::string vvvv = getpos((int)vvv.length() + 3, yy);
// std::cout<<vvvv<<std::endl;
vLabel = atoi(vvvv.c_str());
boost::add_vertex(VertexProperties(vId, vLabel), dataG.back());
}
break;
case 'e': { // std::cout<<yy<<std::endl;
assert(!dataG.empty()); // assert will terminate the program if its argument turns out to be false
int fromId, toId, eLabel;
std::string eee = getpos(2, yy);
// std::cout<<eee<<std::endl;
fromId = atoi(eee.c_str());
std::string eee2 = getpos((int)eee.length() + 3, yy);
// std::cout<<eee2<<std::endl;
toId = atoi(eee2.c_str());
int c = (int)eee.length() + (int)eee2.length() + 4;
// std::cout<<c<<std::endl;
std::string eee3 = getpos(c, yy);
// std::cout<<eee3<<std::endl;
eLabel = atoi(eee3.c_str());
for (size_t i = 0; i < num_vertices(dataG.back()); ++i) // size_t vertice number in the graph
{
if(dataG.back()[i].id==fromId) fromId=i;
else if(dataG.back()[i].id==toId) toId=i;
}
boost::add_edge(fromId, toId, EdgeProperties(eLabel), dataG.back());
} break;
}
}
return dataG;
}
//==============================M A I N P R O G R A M =======================================
int main() {
size_t length;
std::cout << std::boolalpha;
std::vector<Graph> dataG = creategraphs(splitstringtolines(readfromfile("3test.txt", length)));
auto const& graph_small = dataG[0];
auto const& graph_large = dataG[3];
my_callback<Graph, Graph> my_callback(graph_small, graph_large);
std::cout << "equal(graph_small, graph_large,my_callback)=" << vf2_graph_iso(graph_small, graph_large, my_callback) << std::endl;
// first step
{
auto vos = boost::copy_range<std::vector<Graph::vertex_descriptor> >(vertices(graph_small));
std::cout << "equal(graph_small, graph_large,my_callback)=" << vf2_graph_iso(graph_small, graph_large, my_callback, vos, no_named_parameters()) << std::endl;
}
// second step
{
auto vos = boost::copy_range<std::vector<Graph::vertex_descriptor> >(vertices(graph_small));
bool iso = vf2_graph_iso(graph_small, graph_large, my_callback, vos,
edges_equivalent ([&graph_small, &graph_large](Graph::edge_descriptor small_ed, Graph::edge_descriptor large_ed) {
return graph_small[small_ed] == graph_large[large_ed];
}).
vertices_equivalent([&graph_small, &graph_large](Graph::vertex_descriptor small_vd, Graph::vertex_descriptor large_vd) {
return graph_small[small_vd] == graph_large[large_vd];
})
);
std::cout << "equal(graph_small, graph_large,my_callback)=" << iso << std::endl;
}
// third step
{
auto vos = boost::copy_range<std::vector<Graph::vertex_descriptor> >(vertices(graph_small));
bool iso = vf2_graph_iso(graph_small, graph_large, my_callback, vos,
edges_equivalent (make_property_map_equivalent(boost::get(edge_bundle, graph_small), boost::get(edge_bundle, graph_large))).
vertices_equivalent(make_property_map_equivalent(boost::get(vertex_bundle, graph_small), boost::get(vertex_bundle, graph_large)))
);
std::cout << "equal(graph_small, graph_large,my_callback)=" << iso << std::endl;
}
}
打印输出:
equal(graph_small, graph_large,my_callback)=true
equal(graph_small, graph_large,my_callback)=true
equal(graph_small, graph_large,my_callback)=false
equal(graph_small, graph_large,my_callback)=false
[¹] 当然假设你实现了 operator==
对于你的边和顶点属性类型(查看完整列表)
关于c++ - 在 vf2_sub_graph_iso 中使用属性映射进行等价,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30024970/
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这是我的方法 void login(Event event);我想知道 Kotlin 中应该如何 最佳答案 在 Kotlin 中通配符运算符是 * 。它指示编译器它是未知的,但一旦知道,就不会有其他类
看下面的代码 for story in book if story.title.length < 140 - var story
我正在尝试用 C 语言学习字符串处理。我写了一个程序,它存储了一些音乐轨道,并帮助用户检查他/她想到的歌曲是否存在于存储的轨道中。这是通过要求用户输入一串字符来完成的。然后程序使用 strstr()
我正在学习 sscanf 并遇到如下格式字符串: sscanf("%[^:]:%[^*=]%*[*=]%n",a,b,&c); 我理解 %[^:] 部分意味着扫描直到遇到 ':' 并将其分配给 a。:
def char_check(x,y): if (str(x) in y or x.find(y) > -1) or (str(y) in x or y.find(x) > -1):
我有一种情况,我想将文本文件中的现有行包含到一个新 block 中。 line 1 line 2 line in block line 3 line 4 应该变成 line 1 line 2 line
我有一个新项目,我正在尝试设置 Django 调试工具栏。首先,我尝试了快速设置,它只涉及将 'debug_toolbar' 添加到我的已安装应用程序列表中。有了这个,当我转到我的根 URL 时,调试
在 Matlab 中,如果我有一个函数 f,例如签名是 f(a,b,c),我可以创建一个只有一个变量 b 的函数,它将使用固定的 a=a1 和 c=c1 调用 f: g = @(b) f(a1, b,
我不明白为什么 ForEach 中的元素之间有多余的垂直间距在 VStack 里面在 ScrollView 里面使用 GeometryReader 时渲染自定义水平分隔线。 Scrol
我想知道,是否有关于何时使用 session 和 cookie 的指南或最佳实践? 什么应该和什么不应该存储在其中?谢谢! 最佳答案 这些文档很好地了解了 session cookie 的安全问题以及
我在 scipy/numpy 中有一个 Nx3 矩阵,我想用它制作一个 3 维条形图,其中 X 轴和 Y 轴由矩阵的第一列和第二列的值、高度确定每个条形的 是矩阵中的第三列,条形的数量由 N 确定。
假设我用两种不同的方式初始化信号量 sem_init(&randomsem,0,1) sem_init(&randomsem,0,0) 现在, sem_wait(&randomsem) 在这两种情况下
我怀疑该值如何存储在“WORD”中,因为 PStr 包含实际输出。? 既然Pstr中存储的是小写到大写的字母,那么在printf中如何将其给出为“WORD”。有人可以吗?解释一下? #include
我有一个 3x3 数组: var my_array = [[0,1,2], [3,4,5], [6,7,8]]; 并想获得它的第一个 2
我意识到您可以使用如下方式轻松检查焦点: var hasFocus = true; $(window).blur(function(){ hasFocus = false; }); $(win
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