static int provjeriPobjednik(string[,] ploca) {
            if (
                (ploca[0, 0] == "X" && ploca[0, 1] == "X" && ploca[0, 2] == "X") // horizontala 1
                ||
                (ploca[1, 0] == "X" && ploca[1, 1] == "X" && ploca[1, 2] == "X") // horizontala 2
                ||
                (ploca[2, 0] == "X" && ploca[2, 1] == "X" && ploca[2, 2] == "X") // horizontala 3
                ||
                (ploca[0, 0] == "X" && ploca[1, 0] == "X" && ploca[2, 0] == "X") // vertikala 1
                ||
                (ploca[0, 1] == "X" && ploca[1, 1] == "X" && ploca[2, 1] == "X") // vertikala 2
                ||
                (ploca[0, 2] == "X" && ploca[1, 2] == "X" && ploca[2, 2] == "X") // vertikala 3
                ||
                (ploca[0, 0] == "X" && ploca[1, 1] == "X" && ploca[2, 2] == "X") // dijagonala 1
                ||
                (ploca[2, 0] == "X" && ploca[1, 1] == "X" && ploca[0, 2] == "X")) { // dijagonala 2
                return 1;
            }
            if (
                (ploca[0, 0] == "Y" && ploca[0, 1] == "Y" && ploca[0, 2] == "Y") // horizontala 1
                ||
                (ploca[1, 0] == "Y" && ploca[1, 1] == "Y" && ploca[1, 2] == "Y") // horizontala 2
                ||
                (ploca[2, 0] == "Y" && ploca[2, 1] == "Y" && ploca[2, 2] == "Y") // horizontala 3
                ||
                (ploca[0, 0] == "Y" && ploca[1, 0] == "Y" && ploca[2, 0] == "Y") // vertikala 1
                ||
                (ploca[0, 1] == "Y" && ploca[1, 1] == "Y" && ploca[2, 1] == "Y") // vertikala 2
                ||
                (ploca[0, 2] == "Y" && ploca[1, 2] == "Y" && ploca[2, 2] == "Y") // vertikala 3
                ||
                (ploca[0, 0] == "Y" && ploca[1, 1] == "Y" && ploca[2, 2] == "Y") // dijagonala 1
                ||
                (ploca[2, 0] == "Y" && ploca[1, 1] == "Y" && ploca[0, 2] == "Y")) { // dijagonala 2
                return 2;
            }
            return 0;
        }