Ruudukko

input/code.cpp:7:11: error: '::main' must return 'int'
 void main() {
           ^

#include<iostream>
#include<vector>
#include <algorithm>
using namespace std;


void main() {
	int seed;
	cin >> seed;
	vector <int> table;
	table.reserve(seed * seed);
	for (int row = 0; row < seed; row++) { // for each row
		
		vector<int> buff = {};
		for (int b = 1; b <= seed; b++) { // for each number
			buff = {};
			for (int c = 0; c < row; c++) { // for each previous row
				buff.push_back(table[c * (seed) + b-1]); // add numbers up to buffer 
			} 
			for (int d = 0; d < b-1; d++) { // for
				buff.push_back(table[(row)*seed+d]);
			}
			bool found = false;
			int i = 1;
			while (!found) {// check if buffer contains proposed character
				if (!(find(buff.begin(), buff.end(), i) != buff.end())) {
					std::cout << i << " ";
					table.push_back(i);
					if (b == seed) {
						std::cout << std::endl;
					}
					else {
						buff.push_back(i); // add numbers on the left to buffer
					}
					//table.push_back(i);
					found = true;
				}
				i++;
			}
		}
}

	}