vector program

Recently I ran a program, and the result was 2 GB of memory used up, and the result was not calculated. std: bad_alloc appeared. It should be because the memory space in some part of the program was not released in time and the program was checked. It is found that vector is used in many places, and some of them will b

List. For elements that need to be inserted and deleted quickly, you should use the sort List. If you need to quickly access elements randomly, you should use the ArrayList. If the program is in a single-threaded environment or the access is only performed in one thread, the efficiency of non-synchronous classes is high. If multiple threads may operate on one class at the same time, synchronous classes should be used. Pay special attention to the ope

3. one 4. zero 5. zero 6. zero 7. zero8.Two oneThree twoThree oop threeThree four　In addition, Vector plays an important role in parameter transmission.In the Applet, there is a Canvas and a Panel, and the Panel contains the information you want to enter. Based on this information, the parameters are passed to the canvas, in this case, an Interface is used in Java, and a Vector is required to pass these pa

complete copy of an existing vector,For example, vector A constructor with two constant parameters generates a vector with an initial value as an interval. The interval is specified by a semi-open interval [first, last] (the display of MS word may be problematic, first is a left square bracket, last is a right circle bracket.For example,

other sequential containers, and in iterators and references are no better than lists support.The size of the container and the capacity of the container is different, the size refers to the number of elements, the capacity is allocated memory size, capacity is generally equal to or greater than the size of the container, Vector::size () returns the size of the container, vector::capacity () returns the ca

, we can only index the element that already exists in the vector the size () operation returns the number of elements that the vector contains.3. Similarly, when we define a vector with a given size, for example:vectorAny insertion will increase the size of the vector, rather than overwriting an existing element, whi

Recently, the project needs to check whether a large two-dimensional array record has used a data record, so I thought of the way to index memory blocks in the operating system, bitmap can be used to set whether to use and find whether it can be used in O (1) replication. However, in C ++, the storage of Boolean variables is 1 byte (8 bit) storage, resulting in a waste of memory space, because the array may be very large (more than 500 W) So I want to use bitset to implement, however, since the

Will the vector's memory be compromised?Even if it does not leak, how can you reduce the space occupied?We know that Vector has a clear () method?Prototype:#include void clear();The function clear () deletes all elements stored in the vector. If the element of the vector is some object, it invokes their respective destructor (destructor) for each element that is

the memory occupied by the excess. *. Another bad thing about vector is that when you add a member to a vector, all pointers pointing to the original member of this vector cannot be guaranteed to be effective, because the vector will re-alloc memory. however, deque does not. No matter whether a new member is adde

making actual function calls, the compiler expands the code directly when it encounters an inline function. A small library function like size is almost defined as an inline function, so the cost of invoking it at the time of each loop is relatively small.4. Subscript operation does not add elementsNovice C + + programmers may think that vector subscript operations can add elements, but not:Vectorfor (VectorIvec[ix] = IX; Disaster:ivec has no element

Since the last sort endless loop, I feel it is necessary to review the STL container. Vector is the most common and used container in STL. When I read the source code of vector, I still find many traps. These traps may make your program very ugly if you are not careful about them. 1. traps when adding elements The commonly used methods for adding elements in a

device resolution in the Process of display and output. As a vector image format, SVG can correctly express bitmap images in addition to its advantages. 2. SVG is created based on XML XML is W 3c The developed network development language has far more functions than the current HTML language. The XML language provides better management and interaction functions than the HTML language. XML completely separates the content and framework of the

before the insertion point value of the original vector to the new spaceNew_finish = Uninitialized_fill_n (New_finish, n, x);//Fill in new vector with added elements (fill in where current new_finish point)New_finish = uninitialized_copy (position, Finish, new_finish);//Copy the element after the insertion point in the original vextor to the new space} }}Insert n elements in the specified

Label: style HTTP color Io OS AR for SP Both SVM and neural networks can be used for Nonlinear Regression fitting, but their principles are different. SVM is based on the Structure Risk Minimization theory, it is generally considered that the generalization capability is better than that of neural networks. A large number of simulations have proved that SVM is more generalized than neural networks, and can avoid the inherent defect of neural networks-the training results are unstable. This sourc

added or deleted, the iterator is invalidated and the value of the iterator needs to be adjusted. Otherwise, it is very likely to cause a crash at execution time. Point is very important. 3.vector of regular use operationjoin: It is important to note that adding a new element may invalidate the iterator, so the program needs to ensure that the iterator can be updated after the insert or push operation.add

-because it is a front-end rendering display, easy to interact with, and can only control the style in the previous paragraph.Disadvantage-the backend and front end have pressure on the data and presentation data, and when the amount of data is particularly large, front-end rendering consumes performance easily. In this scheme, when we put shp vector data into a text file with certain algorithm, we can avoid the pressure of dynamically acquiring

Differences and usage of arraylist vector sort list Arraylist and vector use arrays to store data. The number of elements in the array is greater than that in the actual storage to add and insert elements. Both allow direct serial number index elements, however, data insertion is designed to move array elements and other memory operations. Therefore, index data is inserted slowly. Because

ArrayList and Vector use arrays to store data. The number of elements in the array is greater than that in the actual storage for adding and inserting elements. Both allow direct serial number index elements. However, inserting data must be designed for memory operations such as array element movement. Therefore, index data is inserted slowly. Because the synchronized method is used for Vector (thread-safe)

Arraylist and vector use arrays to store data. The number of elements in the array is greater than that in the actual data storage to increase the number of inserted elements, however, data insertion involves memory operations such as the movement of array elements. Therefore, data insertion is slow and there are subscripts in the search, so data query is fast; Vector uses the Synchronized Method-thread sec