실패

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
    private static int answer =0;
    private static boolean[][] visit;
    private static char[][] map;
    private static int x, y, k;
    private static int[] dx = {1, 0, -1, 0};
    private static int[] dy = {0, -1, 0, 1};
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        StringTokenizer st = new StringTokenizer(br.readLine());
        x = Integer.parseInt(st.nextToken());
        y = Integer.parseInt(st.nextToken());
        k = Integer.parseInt(st.nextToken()); 
        visit = new boolean[x][y];
        map = new char[x][y];
        
        for(int i=0; i<x;i++){
            st = new StringTokenizer(br.readLine());
            String str = st.nextToken();
            for(int j=0; j<y;j++){
                map[i][j] = str.charAt(j);
            }
        }
        dfs(x-1, 0, 1);
        
        System.out.println(answer);
    }
    public static void dfs(int curX, int curY, int count ){  
        if(count == k){
            if(curX == 0 && curY == y-1){
                answer++;
            }
            return;
        }
        for(int i=0; i<4; i++){
            int newX = curX+dx[i];
            int newY = curY+dy[i]; 
            if(newX < x && newY < y && newY >=0 && newX >=0 
                && map[newX][newY] !='T' ){
                if(!visit[newX][newY]){
                    visit[newX][newY] = true;
                    dfs(newX, newY, count+1);
                    visit[newX][newY]= false; 
                } 
            }
             
        }
    }
}

틀린이유 이며 아래를 시작하기 전에 추가해야하는이유
visit[x-1][0] = true;

dfs(x-1, 0, 1);
시작하는 지점으로 1을 추가해서 시작한다.
현재지점을 우측으로 갔다가 좌측으로 올수도 있다는 것이다.그러니까 출발 지점의 방문 여부도 체크해줘야한다.

완성

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
    private static int answer =0;
    private static boolean[][] visit;
    private static char[][] map;
    private static int x, y, k;
    private static int[] dx = {1, 0, -1, 0};
    private static int[] dy = {0, -1, 0, 1};
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        StringTokenizer st = new StringTokenizer(br.readLine());
        x = Integer.parseInt(st.nextToken());
        y = Integer.parseInt(st.nextToken());
        k = Integer.parseInt(st.nextToken()); 
        visit = new boolean[x][y];
        map = new char[x][y];
        
        for(int i=0; i<x;i++){
            st = new StringTokenizer(br.readLine());
            String str = st.nextToken();
            for(int j=0; j<y;j++){
                map[i][j] = str.charAt(j);
            }
        }
        
        visit[x-1][0] = true;
        dfs(x-1, 0, 1);
        
        System.out.println(answer);
    }
    public static void dfs(int curX, int curY, int count ){ 
        if(count == k){
            if(curX == 0 && curY == y-1){
                answer++;
            }
            return;
        }
        for(int i=0; i<4; i++){
            int newX = curX+dx[i];
            int newY = curY+dy[i]; 
            if(newX < x && newY < y && newY >=0 && newX >=0 
                && map[newX][newY] !='T' ){
                if(!visit[newX][newY]){
                    visit[newX][newY] = true;
                    dfs(newX, newY, count+1);
                    visit[newX][newY]= false; 
                } 
            }
        }
    }
}