We can define 2D Vector as Vector of Vector followed by N number of rows where each of the row is individual a vector. in other words 2D vector is almost similar to a array of vectors but the difference is only in the dynamic properties.

Syntex

vector <vector<data_type>> vector_name;

• vector <vector<int>> vct

Initializition

Here vec is the vector of vectors. where outer vector vec represent row as 2D matrix and every sub vectors represent column elements of particular row vector.

• N = Number of rows
• M - Number of columns Here 2D vector contains N number sub vectors(row) and every sub vector has M number of elements vale of 0

// output of previous initialization 
{ 
  0 0 0 0 
  0 0 0 0
  0 0 0 0 
}

Iteration on 2D vector

• vect.begin() – It returns an iterator to the first vector in a 2-D vector.
• vect.end() – It returns an iterator to the end of the 2-D vector.
• vect.size()– It returns number of elements in vector
• v.push_back – Add vector to the empty 2-D vector
• v.pop_back() – Remove the last vector from a 2-D vector