1
queue<int> q;
2
q.push(start);
3
dist[start] = 0;
4

5
while (!q.empty()) {
6
    int t = q.front();
7
    q.pop();
8

9
    for (int i = h[t]; i != -1; i = ne[i]) {
10
        int j = e[i];
11
        if (dist[j] == -1) {
12
            dist[j] = dist[t] + 1;
13
            q.push(j);
14
        }
15
    }
16
}

1
#include <bits/stdc++.h>
2
using namespace std;
3

4
const int N = 110;
5

6
int n, m;
7
int g[N][N];
8
int dista[N][N];
9
pair<int, int> q[N * N];
10

11
int bfs() {
12
    memset(dista, -1, sizeof dista);
13

14
    int hh = 0, tt = 0;
15
    q[0] = {0, 0};
16
    dista[0][0] = 0;
17

18
    int dx[4] = {-1, 0, 1, 0};
19
    int dy[4] = {0, 1, 0, -1};
20

21
    while (hh <= tt) {
22
        auto t = q[hh++];
23

24
        for (int i = 0; i < 4; i++) {
25
            int x = t.first + dx[i];
26
            int y = t.second + dy[i];
27

28
            if (x >= 0 && x < n && y >= 0 && y < m
29
                && g[x][y] == 0 && dista[x][y] == -1) {
30
                dista[x][y] = dista[t.first][t.second] + 1;
31
                q[++tt] = {x, y};
32
            }
33
        }
34
    }
35

36
    return dista[n - 1][m - 1];
37
}
38

39
int main() {
40
    cin >> n >> m;
41
    for (int i = 0; i < n; i++) {
42
        for (int j = 0; j < m; j++) {
43
            cin >> g[i][j];
44
        }
45
    }
46

47
    cout << bfs() << endl;
48
    return 0;
49
}