alee lee

#include <iostream>
#include <fstream>
using namespace std;

int a[100][100], dl[]={-1, 1, 0 ,0}, dc[]={0, 0, 1, -1}, n, x1, y1, x2, y2, p, u;

struct
{
    int lin, col;

}c[100];

bool ok(int x, int y)
{
    if(a[x][y]!=0 || x>n || y>n || x<1 || y<1)
        return false;
    return true;
}

void citire()
{
    ifstream f("alee.in");
    f>>n;
    f>>x1>>y1>>x2>>y2;
    int i, j;
    while(f>>i>>j)
        a[i][j]=-1;
}

void lee()
{
    int i, j, i_urm, j_urm, dir;
    p=u=1;
    c[1].lin=x1;
    c[1].col=y1;
    a[x1][y1]=1;

    while(p<=u)
    {
        i=c[p].lin;
        j=c[p].col;
        for(dir=0;dir<4;dir++)
        {
            i_urm=i+dl[dir];
            j_urm=j+dc[dir];
            if(ok(i_urm, j_urm)==true)
            {
                u++;
                c[u].lin=i_urm;
                c[u].col=j_urm;
                a[i_urm][j_urm]=a[i][j]+1;
            }
        }
        p++;
    }
}

int main()
{
    citire();
    lee();
    cout<<a[x2][y2];
}
/*
8
2 1 8 8
2 3
3 5
5 7
8 7
6 3
*/