vector GN in cpp

Vector G[N] in C++ is an array of N vectors. It can be declared as follows:

vector G[N];

Here, each element of the array G is a vector of integers. The size of the vector can be changed dynamically at runtime using the push_back() function.

For example, to add an element x to the i-th vector in the array, we can use the following code:

G[i].push_back(x);

Similarly, to access the j-th element of the i-th vector, we can use the following code:

G[i][j]

Overall, using an array of vectors can be useful for storing and manipulating data in a flexible and efficient way.