BFS做法

#include <iostream>
#include <cstring>
#include <queue>
#include <map>
#include <vector>
using namespace std;
const int N = 55;
int R, C;
char s[N][N];
int su1, su2, de1, de2;
int visited[N][N];

vector<pair<int, int>> v;

int x1[4] = {0, 1, -1, 0}, y1[4] = {1, 0, 0, -1};
int x3[2] = {1, -1};
int  bfs(int x, int y) {
    queue<pair<int, int>> q;
    int flagt = 0;
    memset(visited, 0, sizeof visited);
    visited[x][y] = 1;
    q.push({x, y});
    while (!q.empty()) {
        int s1 = q.front().first, s2 = q.front().second;
        if (s[s1][s2] == 'T') {
            flagt = 1;
            if (s[x][y] != 'S') {
                break;
            }
        }
        if ( s[x][y] == 'S' && s[s1][s2] != 'S') {
            v.push_back({s1, s2});
        }
        //else if (s[x][y] != 'S' && s[s1][s2] == 'S') {
        //  flagt = 1;
        //  break;
        //}
        q.pop();
        char dir = s[s1][s2];
        // // // //
        if (dir == 'S' || dir == 'T' || dir == '+') {
            for (int i = 0; i < 4; i++) {
                int s3 = s1 + x1[i], s4 = s2 + y1[i];
                if (!visited[s3][s4] && s[s3][s4] != '#') {
                    visited[s3][s4] = 1;
                    q.push({s3, s4});
                }
            }
        } else if (dir == '-') {
            for (int i = 0; i < 2; i++) {
                int s3 = s1, s4 = s2 + x3[i];
                if (!visited[s3][s4] && s[s3][s4] != '#') {
                    visited[s3][s4] = 1;
                    q.push({s3, s4});
                }
            }
        } else if (dir == '|') {
            for (int i = 0; i < 2; i++) {
                int s3 = s1 + x3[i], s4 = s2;
                if (!visited[s3][s4] && s[s3][s4] != '#') {
                    visited[s3][s4] = 1;
                    q.push({s3, s4});
                }
            }
        } else if (dir == '.') {
            int s3 = s1 + 1, s4 = s2 ;
            if (!visited[s3][s4] && s[s3][s4] != '#') {

                visited[s3][s4] = 1;
                q.push({s3, s4});
            }
        }
    }
    return flagt;
}
int main() {
    int res = 0;
    cin >> R >> C;
    for (int i = 0; i <= R + 1; i++) {
        s[i][0] = '#';
        s[i][C + 1] = '#';
    }
    for (int i = 0; i <= C + 1; i++) {
        s[0][i] = '#';
        s[R + 1][i] = '#';
    }
    for (int i = 1; i <= R; i++)
        for (int j = 1; j <= C; j++) {
            cin >> s[i][j];
            if (s[i][j] == 'S')
                su1 = i, su2 = j;
            if (s[i][j] == 'T')
                de1 = i, de2 = j;
        }
    int flag = bfs(su1, su2);
    //for (int i = 1; i <= R; i++)
    //  for (int j = 1; j <= C; j++) {
    //      cout << s[i][j] << " ";
    //      if (j == C)
    //          cout << endl;
    //  }
    if (flag == 0) {
        cout << "I'm stuck!" << endl;
        return 0;
    }
    for (int i = 0; i < v.size(); i++) {
        if (!bfs(v[i].first, v[i].second))
            res++;
    }
    cout << res << endl;
    return 0;
}