Previous blogs have written about vectors using the sort algorithm, and vector some of the processing methods that have been written before.Just write it today vector . Sort by using the sort algorithm.#include #include #include #include #include BOOLCompare_int (intAMP;LHS,int RHS) {returnLHS > RHS;}BOOLCompare_first_letter (Const STD::unique_ptrSTD::string> AMP;LHS,Const STD::unique_ptrSTD::string> RHS)
Original link: http://blog.csdn.net/cws1214/article/details/47984053
1. Avoid frequent redistribution
One of the most admirable features of STL containers is that they can automatically grow enough to accommodate the data you put in, as long as they are not larger than their maximum size. (To know the maximum value, just call the member function named Max_size.) )
For vectors and strings, if more space is needed, the size is increased by a similar realloc thought. This realloc-like operation ha
In practice, the vector series in c ++-C ++ 11 extends the vector member functions (cbegin (), cend (), crbegin (), crend (), and emplace (), data ())
The emplace_back mentioned above is added to C ++ 11.
Therefore, this blog just wants to list how C ++ 11 expands the vector container.
Std: vector: cbegin and std:
The arraylist, inclulist, and vestor classes all implement the java. util. List interface, but they have different features, mainly as follows:
I,Synchronization
Arraylist and inclulist are not synchronized, while vestor is. Therefore, if thread security is required, arraylist or javaslist can be used to save costs for synchronization. But in the case of multithreading, sometimes we have to use vector. Of course, you can also package arraylist and his
Vector series in practice c ++ -- sort the vector (unique_ptr (string) using the sort algorithm (sort function error "two parameters should be input, but three parameters are provided)
Previously, I wrote a blog post on sorting the vector using the sort algorithm.vector
>
.
Today, let's write a pairvector
>
Use the sort algorithm for sorting.
# In
In practice, the vector series in c ++ -- vector (unique_ptr () initialization (Ownership Transfer)
C ++ 11 provides us with smart pointers and brings us a lot of convenience.
What if unique_ptr is used as an element of the vector container?
The format is exactly the same:vector
> vec;
But how to add elements to vec?
See the following:
# Include
Vector initialization and traversal-dtor-blog
Vector initialization and traversal
STD: Vector
Int
>
Inttest; For(IntI=0; I10;++I){Inttest. push_back (I );} For (STD: Vector Int > : Iterator ITER = Inttest. Begin (); ITER ! = Inttest. End (); ++ ITER){STD: cout * ITER STD: Endl
For vector usage, the additional time consumed by copying data to prevent reallocate memory.
The following two combinations can be used to prevent reallocate.
1. Vector: resize () using array index
2. Vector: Reserve () Use push_back ().
So I tested these two cases on the Windows 2003 platform, and compared them with 3 in which push_back () is directly
Today we want to use vector to realize the function of two-dimensional array, and try to put the two-dimensional vector. Who knows when he got started, he met Ray.
The form of the code is roughly as follows:
VECTOR
The vacuuming operation was performed because the two-dimensional vector was reused. However, th
In practice, the vector series in c ++ -- copy set to vector (do not confuse reserve and resize)
The stl algorithm has a copy function. We can easily write this Code:
#include
#include #include
using namespace std;int _tmain(int argc, _TCHAR* argv[]){ double darray[10]={1.0,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9}; vector
vdouble(10);
more and more widely valued.
Statistical Learning Theory is based on a solid set of theories and provides a unified framework for solving the problem of Finite Sample learning. It can include many existing methods and is expected to help solve many difficult problems (such as Neural Network Structure Selection and Local Minimization). At the same time, based on this theory, a new general learning method-Support Vector Machine (SVM) has been developed
In practice, the vector series in c ++ -- the second worst iterator failed (deleting elements in the vector)
Directly refer to the Code:
# Include
# Include
Using namespace std; int main () {vector
V; v. push_back (1); v. push_back (2); v. push_back (3); std: vector
: Itera
Previous blogs have talked about some of the ways to use Std::find and std::find_ if. But there is no telling of the classes stored in vectors that are defined by themselves. So how do you use Std::find and std::find_if to find it?First define a class:classitem{Private:STD::stringM_itemid;intM_price;intM_count; Public: Item (STD::stringIdintPriceintcount): M_itemid (ID), M_count (count), M_price (price) {}intGetCount ()Const{returnM_count; }STD::stringGetitemid ()Const{returnM_itemid; }intGetPri
The actual deletion element in the C + + vector uses the std::vector::erase () method in the container Vecrot.Std::remove () in C + + does not delete the element because the container's size () does not change, only the replacement of the element.1.std::vector::erase ()Function prototype: Iterator erase (iterator position); Delete the specified elementIterator Er
JDK source code-Vector, jdk-vector1, Vector:-1, an array of objects that can grow. Similar to an object array, it contains an integer index for component access. However, the Vector size can be increased or reduced as needed.-2. Each Vector optimizes storage management by maintaining capacity and capacityIncrement. Cap
I write a simple program to distinguish between the vector container size () and the capacity () function, where the capacity function is to reserve space for the vector container, without having to reallocate the memory every time the element is added, thus improving the efficiency a lot. I through a small program to study, the following is the program and running results, more concise can be seen capacity
JQuery generates the svg vector QR code and jquerysvg Vector
JQuery generates a vector svg QR code and provides PNG and SVG page downloads to relieve pressure on the server.
The Code is as follows:
The above section describes how to use jQuery to generate an svg vector QR code. I hope it will be helpful to you. If you
Vector applications (element traversal, insertion, deletion, switching, etc.), vectorHere is a summary of some common applications of vector containers. For the vector constructor and initialization, refer to http://blog.csdn.net/lsh_2013/article/details/21191289. Element Traversal
Use an iterator to access a vector El
Label: gradient descent method, cut vector, method Vector Zookeeper First, it indicates that the gradient is perpendicular to the cut vector of the curve, that is, the gradient direction is the direction of the normal vector: Set the curve x = x (t), Y = Y (T), and z = z (T) to the surface u (x, y, z) = a curve on C (
C ++ is based on the vector graphics library cairo graphics, vector graphics cairo
// Sudo apt-get install libcairo2-dev // pkg-config -- cflags -- libs cairo //-I/usr/include/cairo-I/usr/include/glib-2.0-I /usr/lib/x86_64-linux-gnu/glib-2.0/include-I/usr/include/pixman-1-I/usr/include/freetype2-I/usr/include/libpng12-lcairo # include
Compilation in Ubuntu:
G ++ 'pkg-config -- cflags cairo 'test_cairo.cpp
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