230417 혼자서 하는 틱택토

private static char[][] graph;
private static int oCount;
private static int xCount;

public static int solution(String[] board) {
    init(board);
    if (xCount > oCount || oCount - xCount > 1) {
        return 0;
    }
    if (win('O') > 0 && win('X') > 0) {
        return 0;
    }
    if (win('O') > 0) {
        if (oCount == xCount) {
            return 0;
        }
    }
    if (win('X') > 0) {
        if (oCount > xCount) {
            return 0;
        }
    }
    return 1;
}

private static void init(String[] board) {
    graph = new char[3][3];
    oCount = 0;
    xCount = 0;
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            graph[i][j] = board[i].charAt(j);
            if (graph[i][j] == 'O') {
                oCount++;
            }
            if (graph[i][j] == 'X') {
                xCount++;
            }
        }
    }
}

public static int win(char c) {
    int count = 0;
    for (int i = 0; i < 3; i++) {
        if (graph[i][0] == c && graph[i][0] == graph[i][1] && graph[i][1] == graph[i][2]) {
            count++;
        }
        if (graph[0][i] == c && graph[0][i] == graph[1][i] && graph[1][i] == graph[2][i]) {
            count++;
        }
    }
    if (graph[0][0] == c && graph[0][0] == graph[1][1] && graph[1][1] == graph[2][2]) {
        count++;
    }
    if (graph[0][2] == c && graph[0][2] == graph[1][1] && graph[1][1] == graph[2][0]) {
        count++;
    }
    return count;
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/160585