#include <algorithm>
#include <iostream>
#include <vector>
 
typedef std::pair<int, int> CellCoordinates;
 
int main()
{
	std::vector<CellCoordinates> cells;
 
	for (int i = 0; i < 3; ++i) {
		for (int j = 0; j < 3; ++j) {
			cells.emplace_back(i, j);
		}
	}
 
	for (int i = 0, size = cells.size(); i < 9; ++i, --size) {
		std::cout << "Cells left: " << size << std::endl;
 
		int index = rand() % (size + 1);
		CellCoordinates cell = cells[index];
 
		std::cout << cell.first << " "
			<< cell.second << std::endl;
 
		std::remove(cells.begin(), cells.end(), cell);
	}
 
	return 0;
}

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