Data Structures

Arrays

Array is just a list of some objects of certain datatype.

We have 1-D and 2-D arrays.

Each element is stored at a certain index and can be accessed using that index.

Vectors or ArrayList

Same as array but elements can be removed or inserted while executing.

Vector 

1. push_back()
2. size()
3. pop_back()
4. empty()
5. clear()
6. erase()

Dictionaries or Hash Tables

Store a list of keys having a value associated with each of them.

Map

1. key and value
2. Values are linked.

Stacks (LIFO)

A list in which only the last element entered can be accessed or manipulated.

Queues (FIFO)

A list of objects in which only initially entered/first element can be accessed or manipulated.

 Sieve of Eratosthenes

generate all prime numbers between two given numbers

int x[100001];
int max=100001;
void sieve()
{ 
for(int i=0;i<max;i++) x[i]=1;
x[0]=x[1]=0;
for(int i=2;i<max;i++)
{
  if(x[i]==1)
  {
   for(int j=2*i;j<max;j+=i) 
   x[i]=0;
   }

}
}
main()
{
int n,m;
cin>>n>>m;
for(int i=n;i<=m;i++) 
{
  if(x[i]==1) print (i);

}
}

Code for Sieve of Eratosthenes​​ :

Questions?

Thank You