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BHAVIN VIRANI

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# 2D Vector in C++

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