使用dfs，根据题目要求搜索满足要求的点即可。

耗时234ms

import java.util.Scanner;

public class Main {
    private static int rows;
    private static int cols;
    private static char[][] map;
    private static int startI, startJ;
    private static int endI, endJ;

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


        boolean[][] startVisited = new boolean[rows][cols];
        getRoads(startI, startJ, startVisited);

        if(!startVisited[endI][endJ]){
            System.out.println("I'm stuck!");
        } else {
            int count = 0;
            for (int i = 0; i < rows; i++) {
                for (int j = 0; j < cols; j++) {
                    if (startVisited[i][j]) {
                        boolean[][] visited = new boolean[rows][cols];
                        getRoads(i, j, visited);
                        if (!visited[endI][endJ])
                            count++;
                    }

                }
            }
            System.out.println(count);
        }
    }

    private static void getRoads(int i, int j, boolean[][] visited) {
        if (i < 0 || i >= rows || j < 0 || j >= cols)
            return;
        if (visited[i][j])
            return;

        char c = map[i][j];
        if (c == '#')
            return;

        visited[i][j] = true;

        switch (c) {
            case '|':
                getRoads(i + 1, j, visited);
                getRoads(i - 1, j, visited);
                break;
            case '.':
                getRoads(i + 1, j, visited);
                break;
            case '+':
            case 'S':
            case 'T':
                getRoads(i + 1, j, visited);
                getRoads(i - 1, j, visited);
                getRoads(i, j - 1, visited);
                getRoads(i, j + 1, visited);
                break;
            case '-':
                getRoads(i, j - 1, visited);
                getRoads(i, j + 1, visited);
                break;
        }
    }
}