Sudoku

#include <iostream>

using namespace std;

string input;
int sudoku[9][9];

bool ok(int number, int row, int col)
{
	for (int i = 0; i < 9; i++) {
		if (sudoku[row][i] == number) return false;
	}
	for (int i = 0; i < 9; i++) {
		if (sudoku[i][col] == number) return false;
	}
	for (int i = 0; i < 3; i++) {
		for (int j = 0; j < 3; j++) {
			if (sudoku[i+row-row%3][j+col-col%3] == number) return false;
		}
	}
	return true;
}

bool solved(int& i, int& j)
{
	for (i = 0; i < 9; i++) {
		for (j = 0; j < 9; j++) {
			if (sudoku[i][j] == 0) return false;
		}
	}
	return true;
}

bool solve()
{
	int row, col;
	if (solved(row,col)) return true;
	for (int number = 1; number <= 9; number++) {
		if (ok(number,row,col)) {
			sudoku[row][col] = number;
			if (solve()) return true;
			sudoku[row][col] = 0;
		}
	}
	return false;
}

int main()
{
	cin >> input;
	for (int i = 0; i < 9; i++) {
		sudoku[0][i] = input[i]-48;
	}
	solve();
	for (int i = 0; i < 9; i++) {
		for (int j = 0; j < 9; j++) {
			cout << sudoku[i][j];
		}
		cout << "\n";
	}
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED