vector of vectors?

[wary veldt]

can anybody tell me what does this do?

vector<vector<int>> dp(n,vector<int>(target+1,0));

[mint coral]

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[surreal venture]

On mobile so I'll check it out better in a bit. A vector of a vector is basically a 2 dimensional array.

You push vectors of ints in the vectors of vectors. Last time I used it was for a grid, it made it easy to access elements with x and y coords. For example: grid[x][y]

[abstract ridge]

It uses constructor 3 twice: https://en.cppreference.com/w/cpp/container/vector/vector

The inner vector makes a vector with target + 1 ints of value 0 and the outer vector puts n of those into dp.

So you sort of end with an n*target+1 matrix filled with 0s.

[wary veldt]

so basically it uses the first n to declare for the outer vector the amount of vectors of size target+1 it has ( so first constructor for the outer declaration and the second is the size of the inner vector declared)

if anybody can confirm this im marking it as solved

[wary veldt]

i am familiar with bidimensional normal arrays, i am unfamiliar with stl vector's syntax

[surreal venture]

Yeah

[wary veldt]

!solved