cpp第一次用set和vector View Code 2761: [JLOI2011]不重复数字 Time Limit: 10 SecMemory Limit: 128 MB Description 给出N个数,要求把其中重复的去掉,只保留第一次出现的数。 例如,给出的数为1 2 18 3 3 19 2 3 6 5 4,其中2和3有重复,去除后的结果为1 2 18 3 19 6 5
vector底层是用数组实现的,每次执行操作,在底层实现时,是会判断当前元素的个数是否等于容量大小,如果没有就直接插入,否则就要扩容了。 void add4() {vector<int> demo{1, 2};demo.push_back(3);//{3,1,2}for (int i = 0; i < demo.size(); i++) {cout << demo[i] << " ";}} ...
vector<int> demo{1, 2}; demo.push_back(3);//{3,1,2} for (int i = 0; i < demo.size(); i++) { cout << demo[i] << " "; } } 换句话说,扩容时是要重新分配大小的,先free掉原来的存储空间,后重新malloc。非常耗费时间! void vector<_Tp, _Allocator>::push_back(const_reference...
set<int> demo{1, 2}; // 如果参数为const vector<int> 需要用const_iterator // vector<int>::const_iterator iter=v.begin(); set<int> s = demo; set<int>::iterator iter; for (iter = s.begin(); iter != s.end(); ++iter) { cout << *iter << " "; } } 删除元素 /* * 删...
1== sizeof(char) <= sizeof(short) <= sizeof(int) <= sizeof(long) <= sizeof(longlong) 由于历史原因,整型的位宽有多种标准: 为解决这一问题,C99/C++11引入了定宽整数类型。 定宽整数类型 定宽整数类型本质上是普通整数类型的类型别名。
deallocate(void*p,size_t n){free(p);}//重新分配内存void*DefaultMalloc::reallocate(void*p,size_t old_sz,size_t new_sz){void*result=realloc(p,new_sz);if(result==0)result=oom_realloc(p,new_sz);returnresult;}//设置内存不在时的处理函数void(*DefaultMalloc::set_malloc_handler(void(*f...
svr.Get("/stream", [&](const Request &req, Response &res) { res.set_content_provider( "text/plain", // Content type [&](size_t offset, DataSink &sink) { if (/* there is still data */) { std::vector<char> data; // prepare data... sink.write(data.data(), data.size()...
{0.0f}; float y{0.0f}; }; then using code to allocate like this: NS::TransferPtr(device->newBuffer(n_elements * sizeof(Coord_f), MTL::ResourceStorageModeManaged)) The headers for metal-cpp do not appear to define vector objects like float2, but I'm doubtless missing something. ...
vector<long>q;std::cout.imbue(std::locale("en_US.UTF-8"));std::cout<<std::uppercase<<"p.max_size() = "<<std::dec<<p.max_size()<<" = 0x"<<std::hex<<p.max_size()<<'\n'<<"q.max_size() = "<<std::dec<<q.max_size()<<" = 0x"<<std::hex<<q.max_size()<...
void *operator new (size_t size) { cout << "新的new:" << size << endl; return malloc(size); } void operator delete(void *p) { //释放由p指向的存储空间 cout << "新的delete" << endl; free(p); } ... ... 继承 class A:[private/protected/public] B 默认为private继承 A是基类...