有一点推简单了

#include<bits/stdc++.h>
using namespace std;
char a[105][105];
int dx[4] = {1,-1,0,0},dy[4] = {0,0,1,-1},vis[105][105];

struct node{
    int x,y,step;
};

int main(){
    queue<node> q;
    int n,m,sx,sy;
    cin >> n >> m;
    for(int i = 0;i < n;i ++){
        for(int j = 0;j < m;j ++){
            cin >> a[i][j];
            if(a[i][j] == 'S'){
                sx = i;
                sy = j;
            }
        }
    }
    q.push({sx,sy,0});
    while(!q.empty()){
        int ix = q.front().x;
        int iy = q.front().y;
        int istep = q.front().step;
        q.pop();
        if(a[ix][iy] == 'T'){
            cout << istep;
            return 0;
        }
        for(int i = 0;i < 4;i ++){
            int nx = ix + dx[i];
            int ny = iy + dy[i];
            if(nx >= 0 and ny >= 0 and nx < n and ny < m and vis[nx][ny] == 0 and a[nx][ny] != '#'){
                vis[nx][ny] = 1;
                q.push({nx,ny,istep + 1});
            }
        }
    }
    cout << -1;
    return 0;
}