1、深搜找到起點可以到達的所有點，如果其中不包括終點，輸入I'm stuck

2、深搜每一個起點可到達的點，如果其不可以到達終點，計數器加一

奉上java滿分程式碼

import java.util.Scanner;

public class Main {
    private static char[][] map;
    private static int r, c;

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String[] firstLine = scanner.nextLine().split(" ");
        r = Integer.parseInt(firstLine[0]);
        c = Integer.parseInt(firstLine[1]);
        map = new char[r][c];
        int startI = 0, startJ = 0, endI = 0, endJ = 0;
        for(int i = 0; i < r; i++){
            String line = scanner.nextLine();
            for(int j = 0; j < c; j++){
                char ch = line.charAt(j);
                map[i][j] = ch;
                if(ch == 'S'){
                    startI = i;
                    startJ = j;
                } else if(ch == 'T'){
                    endI = i;
                    endJ = j;
                }
            }
        }
        scanner.close();

        boolean[][] canStartArrivePoints = new boolean[r][c];
        getReachablePoints(startI, startJ, canStartArrivePoints);
        if(canStartArrivePoints[endI][endJ]){
            int count = 0;
            for(int i = 0; i < r; i++){
                for(int j = 0; j < c; j++){
                    if(canStartArrivePoints[i][j]){
                        boolean[][] points = new boolean[r][c];
                        getReachablePoints(i, j , points);
                        if(!points[endI][endJ])
                            count++;
                    }
                }
            }
            System.out.println(count);
        } else{
            System.out.println("I'm stuck!");
        }
    }

    private static void getReachablePoints(int i , int j, boolean[][] points){
        if(i < 0 || j < 0 || i > r - 1 || j > c - 1)
            return;
        if(points[i][j])
            return;
        char ch = map[i][j];
        if(ch == '#')
            return;
        points[i][j] = true;
        switch (ch){
            case 'S':
            case 'T':
            case '+':
                getReachablePoints(i - 1, j, points);
                getReachablePoints(i + 1, j, points);
                getReachablePoints(i, j - 1, points);
                getReachablePoints(i, j + 1, points);
                break;
            case '-':
                getReachablePoints(i, j - 1, points);
                getReachablePoints(i, j + 1, points);
                break;
            case '|':
                getReachablePoints(i - 1, j, points);
                getReachablePoints(i + 1, j, points);
                break;
            case '.':
                getReachablePoints(i + 1, j, points);
                break;
        }
    }

}