STD: Difference Between Reserve and resize of Vector1. Reserve: Allocate space, change capacity but not size2.Resize: Allocate space. Changing the capacity also changes the size.
If you know the vector size, resize it as an array without allocating extra memory.
ReserveIt is a container reserved space, but does not actually create element objects. Before creating an object, you cannot reference the elements in the container. Therefore, when add
There is a copy function in the STL algorithm. We can easily write this code:#include #include #include using namespace STD;int_tmain (intARGC, _tchar* argv[]) {Doubledarray[Ten]={1.0,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9}; vectordouble>Vdouble (Ten); vectordouble>:: Iterator Outputiterator=vdouble.begin (); Copy (darray,darray+Ten, Outputiterator); while(Outputiterator!=vdouble.end ()) {coutreturn 0;}So you want to use copy to set the to vector, so you
Recently want to learn the next Lucene, the previous run of the demo will feel very magical, what principle, especially to find the highest similarity, the best results. Simply jump directly to this question, a lot of data are mentioned in the VSM (vector space model) is a vector spatial models, according to this model can be the search results of the optimization of the screening, and currently do not know
Vector series in practice c ++ -- using vector to construct two-dimensional arrays
2D arrays are sometimes used, but few use vector to construct a 2D array.
First of all, it should be clear that there is no two-dimensional array in the computer world, just a concept of the user. In fact, our so-called two-dimensional array must also be a continuous memory.
In
Dynamically assigned vector pointer Vector If it is a dynamically allocated vector pointer, you can only use the array method (the above Code is red) when inserting elements into the vector. the push_back () function has an error. Why? Use the shared_ptr vector point
C ++ learning notes (16): perform more operations on vector-generic algorithms and learning notes vector
Emphasize that the generic algorithm here is not only for vector operations, but for "sequential containers.
But what is an ordered container:
We all know that containers are collections of certain types of objects. Ordered containers provide programmers with
The Int size is 4, and the vector
# Include
Output result:
201 ...... 20100 press any key to continue...
We can see that:Sizeof (VEC) depends only on the Data Type stored in the vector and has nothing to do with the number of elements. This value should be related to the compiler.
# Include
Output:
Sizeof (vector
Why is the size 20, and so
Previously, the Insert () method for vectors was used to insert the elements of vector b into vector a. We can imagine the results in vector a, but what about the elements in vector b?Look at the program that you've written before:#include #include intMain () {STD:: vectorint>Myvector (3, -);STD:: vectorint>:: Iterator
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)
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
distributional Vector VS. Distributed Vector
Similarities and differences.
For natural language the same pointare based on distribution ideas using the same corpus distributional models (Bow,lsi,lda)Altogether now the same text area morphemes (such as the same statement) related, the more common statements in the corpus, the more relevant to use the number of common statements to construct words and words
Shocked! Vector two lines of code to reverse order, six lines of code through the normal balancing tree, vector Reverse OrderReturns the reverse order of two lines of code in Vector.
Background
First, let's think about the Bubble sorting process. It's not hard to find that for each element, we actually keep comparing and exchanging with the previous element.
It i
Deep Learning of Vector sets and deep learning of vector
First, Vector is the list implementation provided by JDK. Like ArrayList, Vector is also implemented based on arrays.
Create an array of 10, assign values to the elementData object, and set capacityIncrement to 0.
The add method in the
When using STL containers (such as map, list, vector, etc.), whether to put an object or an object pointer, that is, vector
First of all, to illustrate, these two ways, how to use the function can be achieved, a group of integers into the container. First look at the difference between the two ways in use.
1.vector
Copy Code code as follows:
Vect
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
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