Difference Between Vector vs List

Vector vs List
Often confusing to the programmers, vectors and lists are sequences used in array holdings in C++ and Java. The two terms hold array addresses but with different methods of holding arrays.
The basic thing we need to know is that an array is a “list” which holds some or all of the data, i.e., integers, floating points, or characters and is defined in brackets “[].”
Actually, vectors and lists act according to the instances. So let’s have a look at these two terms one by one.
Vectors
Vectors are used in array holding and elements accessing. Here you can access any element randomly using the “[]” operator. So it becomes easy to look through all the elements or one specific element with a vector operation. So if you insert any object in the end, in the beginning, or in the middle, then vectors have a plus point because you can access the random address and make changes there. However, vectors are a bit slow as compared to list objects. Vectors are considered as synchronized objects, efficient in random access, and they properly hold the data with a synced list. A vector is picked whenever there is no need to insert or delete in the
middle (list) or from the front.
The number of elements in an array may vary dramatically.
Example:
vector V;
V.insert(V.begin(), 3);
assert(V.size() == 1 && V.capacity() >= 1 && V[0] == 3);
Lists
Lists are “double linked sequences” supporting both forward and backward traversal. The time taken in the insertion and deletion in the beginning, end, and in the middle is constant. Insertion and splicing between linked lists do not invalidate any iteration in the elements. Only removal invalidates the iteration. They are not synchronized so they are not accessible randomly. The ordering of iterations may change according to user, but it does not affect any changes in the elements. They are faster than vectors and are ideal for insertion and deletion in the beginning, middle, and end of the element lists.
Example:
#include
// list class-template definition
….
int main()
{
int array[ 4 ] = { 2, 6, 4, 8 };
std::list< int > values;
std::list< int > otherValues;
Summary:
1. A list is not synchronized while a vector is.
2. Lists have no default size while a vector has a default size of 10.
3. Lists and vectors are both dynamically growing arrays.
4. A list is not thread safe whereas a vector is thread safe.
5. Lists, as they apply only to addition and deletion in the front and rear, are faster while
vectors take more CPU.
6. A vector grows by its size twice while a list decreases to half, i.e., 50 per cent.

Comments

Post a Comment

Popular posts from this blog

Smart Pointers in C++ and How to Use Them

Image
  Smart Pointers in C++ and How to Use Them In this article, we will be discussing smart pointers in C++. What are Smart Pointers, why, and how to use them properly? Pointers are used for accessing the resources which are external to the program – like heap memory. So, for accessing the heap memory (if anything is created inside heap memory), pointers are used. When accessing any external resource we just use a copy of the resource. If we make any change to it, we just change it in the copied version. But, if we use a pointer to the resource, we’ll be able to change the original resource. Play Video Click here for the Complete Course! Problems with Normal Pointers Take a look at the code below. C++ #include <iostream> using namespace std;   class Rectangle { private :      int length;      int breadth; };   void fun() {      // By taking a pointer p and      // dynamically creating object      // of class rectangle      Rectangle* p = new Rectangle(); }   int main() {    
Read more

Operator Overloading in C++

Operator Overloading in C++ In C++, we can make operators to work for user defined classes. For example, we can overload an operator ‘+’ in a class like String so that we can concatenate two strings by just using +. Other example classes where arithmetic operators may be overloaded are Complex Number, Fractional Number, Big Integer, etc. A simple and complete example #include<iostream> using namespace std;   class Complex { private :      int real, imag; public :      Complex( int r = 0, int i =0)  {real = r;   imag = i;}             // This is automatically called when '+' is used with      // between two Complex objects      Complex operator + (Complex const &obj) {           Complex res;           res.real = real + obj.real;           res.imag = imag + obj.imag;           return res;      }      void print() { cout << real << " + i" << imag << endl; } };   int main()
Read more

How would you read in a string of unknown length without risking buffer overflow

How would you read in a string of unknown length without risking buffer overflow #include <stdio.h> #include <stdlib.h> char * inputString ( FILE * fp , size_t size ){ //The size is extended by the input with the value of the provisional char * str ; int ch ; size_t len = 0 ; str = realloc ( NULL , sizeof ( char )* size ); //size is start size if (! str ) return str ; while ( EOF !=( ch = fgetc ( fp )) && ch != '\n' ){ str [ len ++]= ch ; if ( len == size ){ str = realloc ( str , sizeof ( char )*( size += 16 )); if (! str ) return str ; } } str [ len ++]= '\0' ; return realloc ( str , sizeof ( char )* len ); } int main ( void ){ char * m ; printf ( "input string : " ); m = inputString ( stdin , 10 ); printf ( "%s\n" , m ); free ( m ); return 0 ; }
Read more