Revise paste Untitled

#include <iostream>
#include <queue>
#include <vector>
using namespace std;
const int maxn = 105;
char mat[maxn][maxn];
int main() {
    int n, m;
    cin >> n >> m;
    
    int si, sj;
    int ei, ej;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            cin >> mat[i][j];
            
            if(mat[i][j] == 'S') {
                si = i;
                sj = j;
            }
            if(mat[i][j] == 'E') {
                ei = i;
                ej = j;
            }
        }
    }
    
    vector<vector<bool>> visited(n, vector<bool>(m, false));
    visited[si][sj] = true;
    int di[] = {-1, 1, 0, 0};
    int dj[] = {0, 0, -1, 1};
    queue<int> q;
    q.push(si);
    q.push(sj);
    q.push(0);
    
    while(!q.empty()) {
        int ci = q.front();
        q.pop();
        int cj = q.front();
        q.pop();
        int dist = q.front();
        q.pop();
        
        if(ci == ei and cj == ej) {
            cout << dist << endl;
            break;
        }
        
        for(int k = 0; k < 4; k++) {
            int ti = ci + di[k];
            int tj = cj + dj[k];
            
            if(ti >= 0 and ti < n and tj >= 0 and tj < m and !visited[ti][tj] and mat[ti][tj] != '#') {
                q.push(ti);
                q.push(tj);
                q.push(dist + 1);
                
                visited[ti][tj] = true;
            }
        }
        
    }
    return 0;
}