本地通过，洛谷CE？

/*

*/
#include <iostream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <cstring>
#include <algorithm>
#include <cstdlib>
#include <map>
#include <set>
#include <ctime>
#include <queue>
#include <iomanip>

using namespace std;
const int N = 1e3 + 10;
int dx[4] = {1, -1, 0, 0};
int dy[4] = {0, 0, -1, 1};
int n;
int step[N][N];
int x1, y1,x2, y2;
bool use[N][N];
int ans;
char a[N][N];

void bfs(int x, int y)
{
    queue < pair<int,int> > q;
    q.push(make_pair(x, y));
    use[x][y] = true;
    while(q.size())
    {
        int x = q.front().first;
        int y = q.front().second;
//      if(x == x1 && y == y1)
//      {
//          ans = step[x][y];
//          return;
//      }
        q.pop();
        for(int i = 0; i < 4; i++)
        {
            int bx = x + dx[i];
            int by = y + dy[i];
            if(1 <= bx && bx <= n && 1 <= by && by <= n && a[bx][by] != '1' && use[bx][by] == false)
            {
                use[bx][by] = true;
                step[bx][by] = step[x][y] + 1;
                q.push(make_pair(bx, by));
            }
        }
    }
}

int main()
{
    cin >> n;
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= n; j++)
            cin >> a[i][j];
    cin >> x2 >> y2 >> x1 >> y1;
    bfs(x2, y2);

    cout << step[x1][y1];
    return 0;
}