[삼성기출]백준14890 - 경사로

package sw;

import java.io.*;

public class Main14890_경사로 {

	static int N,L;
	static int[][] map;
	static boolean check(int x, int y) {
		if(x>=0 && x<map.length && y>=0 && y<map[x].length)
			return true;
		else return false;
	}
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] input = br.readLine().trim().split(" ");
		
		N = Integer.parseInt(input[0]);
		L = Integer.parseInt(input[1]);
		map = new int[N][N];
		for(int i=0; i<N; i++) {
			input = br.readLine().trim().split(" ");
			for(int j=0; j<N; j++) {
				map[i][j] = Integer.parseInt(input[j]);
			}
		}
		
		int res = 0;
		int state, direct;
		boolean canWay;
		boolean visit[];
		for(int i=0; i<N; i++) {
			state = 0;
			direct = 0;
			canWay = true;
			visit = new boolean[N];
			for(int j=1; j<N; j++) {
				state = checkUpAndDown(i,j,direct);
				if(state == -1) {
					canWay = canWay(i,j,direct,state, visit);
				}else if(state == 1) {
					canWay = canWay(i,j,direct,state, visit);
				}else if(state == 0) {
					continue;
				}else canWay = false;
				if(!canWay) break;
				if(state == -1) j+=(L-1);
			}
			if(canWay) res++;
		}
		
		for(int j=0; j<N; j++) {
			state = 0;
			direct = 1;
			canWay = true;
			visit = new boolean[N];
			for(int i=1; i<N; i++) {
				state = checkUpAndDown(i,j,direct);
				if(state == -1) {
					canWay = canWay(i,j,direct,state,visit);
				}else if(state == 1) {
					canWay = canWay(i,j,direct,state,visit);
				}else if(state == 0) {
					continue;
				}else canWay = false;
				if(!canWay) break;
				if(state == -1) i+=(L-1);
				
			}
			if(canWay) res++;
		}
		
		System.out.println(res);
	}
	
	/*
	 * return
	 * -1: down
	 * 1 : up
	 * 0 : flat
	 * -2 : false
	 */
	static int checkUpAndDown(int x, int y, int d) {
		if(d==0) {
			if(map[x][y] - map[x][y-1] == -1) {
				return -1;
			}else if(map[x][y] - map[x][y-1] == 1) {
				return 1;
			}else if(map[x][y] == map[x][y-1]) {
				return 0;
			}else return -2;
		}else {
			if(map[x][y] - map[x-1][y] == -1) {
				return -1;
			}else if(map[x][y] - map[x-1][y] == 1) {
				return 1;
			}else if(map[x][y] == map[x-1][y]) {
				return 0;
			}else return -2;
		}
	}
	
	// d==1 우, d==0 하 
	static boolean canWay(int x, int y, int d, int state, boolean[] visit) {
		if(d == 0) {
			if(state == -1) {
				int h = map[x][y];
				for(int j=y; j<y+L; j++) {
					if(!check(x,j) || map[x][j] != h) return false;
					if(visit[j]) return false;
					visit[j] = true;
				}
			}else if(state == 1) {
				int h = map[x][y-1];
				for(int j=y-1; j>=y-L; j--) {
					if(!check(x,j) || map[x][j] != h) return false;
					if(visit[j]) return false;
					visit[j] = true;
				}
			}
		}else if(d == 1) {
			if(state == -1) {
				int h = map[x][y];
				for(int i=x; i<x+L; i++) {
					if(!check(i,y) || map[i][y] != h) return false;
					if(visit[i]) return false;
					visit[i] = true;
				}
			}else if(state == 1) {
				int h = map[x-1][y];
				for(int i=x-1; i>=x-L; i--) {
					if(!check(i,y) || map[i][y] != h) return false;
					if(visit[i]) return false;
					visit[i] = true;
				}
			}
		}
		return true;
	}
}