[백준 14500] 테트로미노

 

N*M 배열에서 테트로미노를 놓을 수 있는 경우를 모두 체크한다.

 

코드를 보면 구현방식을 아주 쉽게 알 수 있다.

 

public class Main {
    
    static int a[][];
    
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        
        st = new StringTokenizer(br.readLine());
        int n = Integer.parseInt(st.nextToken());
        int m = Integer.parseInt(st.nextToken());
        a = new int[n][m];
        
        for(int i=0; i<n; i++) {
            st = new StringTokenizer(br.readLine());
            for(int j=0; j<m; j++)
                a[i][j] = Integer.parseInt(st.nextToken());
        }
        
        int max = 0;
        for(int i=0; i<n; i++) {
            for(int j=0; j<m; j++) {
                if(i+1 < n && j+2 < m) {
                    /* ㅁㅁ
                     *   ㅁㅁ
                     */
                    int sum = a[i][j] + a[i][j+1] + a[i+1][j+1] + a[i+1][j+2];
                    max = Math.max(max, sum);
                    /*   ㅁㅁ
                     * ㅁㅁ
                     */
                    sum = a[i][j+1] + a[i][j+2] + a[i+1][j] + a[i+1][j+1];
                    max = Math.max(max, sum);
                    /* ㅁㅁㅁ
                     * ㅁ
                     */
                    sum = a[i][j] + a[i][j+1] + a[i][j+2] + a[i+1][j];
                    max = Math.max(max, sum);
                    /* ㅁㅁㅁ
                     *     ㅁ
                     */
                    sum = a[i][j] + a[i][j+1] + a[i][j+2] + a[i+1][j+2];
                    max = Math.max(max, sum);
                    /* ㅁ
                     * ㅁㅁㅁ
                     */
                    sum = a[i][j] + a[i+1][j] + a[i+1][j+1] + a[i+1][j+2];
                    max = Math.max(max, sum);
                    /*     ㅁ
                     * ㅁㅁㅁ
                     */
                    sum = a[i][j+2] + a[i+1][j] + a[i+1][j+1] + a[i+1][j+2];
                    max = Math.max(max, sum);
                    /*   ㅁ
                     * ㅁㅁㅁ
                     */
                    sum = a[i][j+1] + a[i+1][j] + a[i+1][j+1] + a[i+1][j+2];
                    max = Math.max(max, sum);
                    /* ㅁㅁㅁ
                     *   ㅁ
                     */
                    sum = a[i][j] + a[i][j+1] + a[i+1][j+1] + a[i][j+2];
                    max = Math.max(max, sum);
                }
                if(i+2 < n && j+1 < m) {
                    /* ㅁ
                     * ㅁㅁ
                     *   ㅁ
                     */
                    int sum = a[i][j] + a[i+1][j] + a[i+1][j+1] + a[i+2][j+1];
                    max = Math.max(max, sum);
                    /*   ㅁ
                     * ㅁㅁ
                     * ㅁ
                     */
                    sum = a[i][j+1] + a[i+1][j] + a[i+1][j+1] + a[i+2][j];
                    max = Math.max(max, sum);
                    /* ㅁ
                     * ㅁ
                     * ㅁㅁ
                     */
                    sum = a[i][j] + a[i+1][j] + a[i+2][j] + a[i+2][j+1];
                    max = Math.max(max, sum);
                    /*   ㅁ
                     *   ㅁ
                     * ㅁㅁ
                     */
                    sum = a[i][j+1] + a[i+1][j+1] + a[i+2][j] + a[i+2][j+1];
                    max = Math.max(max, sum);
                    /* ㅁㅁ
                     * ㅁ
                     * ㅁ
                     */
                    sum = a[i][j] + a[i][j+1] + a[i+1][j] + a[i+2][j];
                    max = Math.max(max, sum);
                    /* ㅁㅁ
                     *   ㅁ
                     *   ㅁ
                     */
                    sum = a[i][j] + a[i][j+1] + a[i+1][j+1] + a[i+2][j+1];
                    max = Math.max(max, sum);
                    /* ㅁ
                     * ㅁㅁ
                     * ㅁ
                     */
                    sum = a[i][j] + a[i+1][j] + a[i+1][j+1] + a[i+2][j];
                    max = Math.max(max, sum);
                    /*   ㅁ
                     * ㅁㅁ
                     *   ㅁ
                    */
                    sum = a[i][j+1] + a[i+1][j] + a[i+1][j+1] + a[i+2][j+1];
                    max = Math.max(max, sum);
                }
                if(j+3 < m) {
                    /* ㅁㅁㅁㅁ
                     */
                    int sum = a[i][j] + a[i][j+1] + a[i][j+2] + a[i][j+3];
                    max = Math.max(max, sum);
                }
                if(i+3 < n) {
                    /* ㅁ
                     * ㅁ
                     * ㅁ
                     * ㅁ
                     */
                    int sum = a[i][j] + a[i+1][j] + a[i+2][j] + a[i+3][j];
                    max = Math.max(max, sum);
                }
                if(i+1 < n && j+1 < m) {
                    /* ㅁㅁ
                     * ㅁㅁ
                     */
                    int sum = a[i][j] + a[i+1][j] + a[i][j+1] + a[i+1][j+1];
                    max = Math.max(max, sum);
                }
            }
        }
        System.out.println(max);
    }
}