#include <iostream>
#include <vector>
#include <algorithm>
/*
Create a sorted unique array (vec) from a matrix (vec of vec).
The idiomatic approach uses:
- std::set for uniqueness + automatic sorting
- or std::vector + sort + unique for full control
*/
// Idiomatic using vector + sort + unique
std::vector<int> make_sorted_unique_vec(const std::vector<std::vector<int>>& mat) {
std::vector<int> vec;
// Flatten matrix into vec
for (const auto& slc : mat) {
vec.insert(vec.end(), slc.begin(), slc.end());
}
// Sort
std::sort(vec.begin(), vec.end());
// Remove duplicates
vec.erase(std::unique(vec.begin(), vec.end()), vec.end());
return vec;
}
int main()
{
std::vector<std::vector<int>> mat = {
{5, 1, 17, 3, 8, 2, 1, 9},
{3, 5, 7, 4, 2, 3, 4, 1},
{9, 1, 8, 2, 3, 88, 17, 5}
};
auto vec = make_sorted_unique_vec(mat);
for (int x : vec) std::cout << x << " ";
}
/*
run:
1 2 3 4 5 7 8 9 17 88
*/
