TreasureHunt

Code

public class TreasureHunt

{    

    int xLen,yLen;

    char[][] land;

    String[] inst;

    boolean instCheck(int x, int y) {

        int[] dx = {0,-1,1,0};

        int[] dy = {-1,0,0,1};

        for (int k = inst.length-1; k >= 0; k--) {

            char d = inst[k].charAt(0);

            int p = inst[k].charAt(2)-'0';

            if (d == 'W') {

                while(p-->0)

                    if(++x>=xLen || land[y][x]!='O') return false;

            }

            else if (d == 'E') {

                while(p-->0)

                    if(--x<0 || land[y][x]!='O') return false;

            }

            else if (d == 'N') {

                while(p-->0)

                    if(++y>=yLen || land[y][x]!='O') return false;

            }

            else {

                while(p-->0)

                    if(--y<0 || land[y][x]!='O') return false;

            }

        }

        for (int i=0; i < 4; i++) {

            int x1 = x+dx[i];

            int y1 = y+dy[i];

            if(x1<0 || y1<0 || x1>=xLen || y1>=yLen || land[y1][x1] == '.') return true;

        }

        return false;

    }

    public int[] findTreasure(String[] island, String[] instructions) {

        land = new char[island.length][];

        for (int i=0; i < land.length; i++)

            land[i] = island[i].toCharArray();

        inst = instructions;

        int[] mx = new int[]{0,-1,1,0,-1,1,-1,1};

        int[] my = new int[]{-1,0,0,1,-1,-1,1,1};

        xLen = land[0].length;

        yLen = land.length;

        int iLen = (xLen > yLen) ? xLen : yLen;

        int cx=0, cy=0;

        LOOP:

        for (int i=0; i < land.length; i++) {

            for (int j=0; j < land[0].length; j++) {

                if (land[i][j] == 'X') {

                    cx = j;

                    cy = i;

                    land[i][j] = 'O';

                    break LOOP;

                }

            }

        }

        if(instCheck(cx,cy)) return new int[]{cx,cy};

        for (int i=1; i <= iLen; i++) {

            for (int j=0; j < 4; j++) {

                int x = cx + mx[j];

                int y = cy + my[j];

                if(mx[j] > 0) mx[j]++;

                else if(mx[j] < 0) mx[j]--;

                if(my[j] > 0) my[j]++;

                else if(my[j] < 0) my[j]--;

                if(x<0 || y<0 || x>=xLen || y>=yLen || land[y][x]=='.') continue;

                if(instCheck(x,y)) {return new int[]{x,y};}

            }

            for (int j=1; j < i; j++) {

                // top

                int x = cx-j;

                int y = cy-i;

                if(x>=0 && y>=0 && land[y][x]!='.' && instCheck(x,y)) return new int[]{x,y};

                x = cx+j;

                if(y>=0 && x<xLen && land[y][x]!='.' && instCheck(x,y)) return new int[]{x,y};

                // both sides of the center

                x = cx-i;

                y = cy-j;

                if(x>=0 && y>=0 && land[y][x]!='.' && instCheck(x,y)) return new int[]{x,y};

                x = cx+i;

                if(y>=0 && x<xLen && land[y][x]!='.' && instCheck(x,y)) return new int[]{x,y};

                x = cx-i;

                y = cy+j;

                if(x>=0 && y<yLen && land[y][x]!='.' && instCheck(x,y)) return new int[]{x,y};

                x = cx+i;

                if(x<xLen && y<yLen && land[y][x]!='.' && instCheck(x,y)) return new int[]{x,y};

                // bottom

                x = cx-j;

                y = cy+i;

                if(x>=0 && y<yLen && land[y][x]!='.' && instCheck(x,y)) return new int[]{x,y};

                x = cx+j;

                if(x<xLen && y<yLen && land[y][x]!='.' && instCheck(x,y)) return new int[]{x,y};

            }

            for (int j=4; j < 8; j++) {

                int x = cx + mx[j];

                int y = cy + my[j];

                if(mx[j] > 0) mx[j]++;

                else if(mx[j] < 0) mx[j]--;

                if(my[j] > 0) my[j]++;

                else if(my[j] < 0) my[j]--;

                if(x<0 || y<0 || x>=xLen || y>=yLen || land[y][x]=='.') continue;

                if(instCheck(x,y)) {return new int[]{x,y};}

            }

        }

        return new int[]{};

    }

}

Explanation

X를 기준으로 +(상좌우하) / [상좌우하]와 [좌상,우상,좌하,우하]를 제외한 현재 이동 횟수에 있는 칸들의 최상단부터 최하단 / X(좌상,우상,좌하,우하) 순으로 탐색해 나간다. 유클리디안 거리를 기준으로 순서를 정해놨기 때문에 유클리디안 거리를 계산하여 비교할 필요없이 원하는 결과를 찾으면 바로 x,y 좌표를 반환한다.