#include <vector>
#include <algorithm>
#include <iostream>
#include <iomanip>
 
using namespace std;
 
 
int main(int argc, const char * argv[])
{
    int n = 5;
 
    vector<int> p1_flat;
    for(int i = 0; i < n*n; ++i) p1_flat.push_back(i);
 
    vector<vector<int>> p1(n,vector<int>(n));
 
    for(int i = 0; i < n; ++i)
        copy_n(p1_flat.begin()+i*n,n,p1[i].begin());
 
    for(auto a: p1)
    {
        for(auto b: a) cout << setw(2) << b << " ";
        cout << endl;
    }
 
 
}
 

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