Один конь

#include <bits/stdc++.h>

using namespace std;

const int N = 22;

int n;
int f1, s1;
int f2, s2;
int used[N][N];
int dist[N][N];

int main() {
    cin >> n;

    cin >> f1 >> s1;
    cin >> f2 >> s2;

    queue < pair <int, int> > q;
    used[f1][s1] = 1;
    q.push({f1, s1});

    while (!q.empty()) {
        int x = q.front().first, y = q.front().second;
        q.pop();
        if (x - 1 >= 1 && y - 2 >= 1 && !used[x - 1][y - 2]) {
            used[x - 1][y - 2] = 1;
            dist[x - 1][y - 2] = dist[x][y] + 1;
            q.push({x - 1, y - 2});
        }
        if (x - 1 >= 1 && y + 2 <= n && !used[x - 1][y + 2]) {
            used[x - 1][y + 2] = 1;
            dist[x - 1][y + 2] = dist[x][y] + 1;
            q.push({x - 1, y + 2});
        }
        if (x + 1 <= n && y - 2 >= 1 && !used[x + 1][y - 2]) {
            used[x + 1][y - 2] = 1;
            dist[x + 1][y - 2] = dist[x][y] + 1;
            q.push({x + 1, y - 2});
        }
        if (x + 1 <= n && y + 2 <= n && !used[x + 1][y + 2]) {
            used[x + 1][y + 2] = 1;
            dist[x + 1][y + 2] = dist[x][y] + 1;
            q.push({x + 1, y + 2});
        }
        if (x - 2 >= 1 && y - 1 >= 1 && !used[x - 2][y - 1]) {
            used[x - 2][y - 1] = 1;
            dist[x - 2][y - 1] = dist[x][y] + 1;
            q.push({x - 2, y - 1});
        }
        if (x - 2 >= 1 && y + 1 <= n && !used[x - 2][y + 1]) {
            used[x - 2][y + 1] = 1;
            dist[x - 2][y + 1] = dist[x][y] + 1;
            q.push({x - 2, y + 1});
        }
        if (x + 2 <= n && y - 1 >= 1 && !used[x + 2][y - 1]) {
            used[x + 2][y - 1] = 1;
            dist[x + 2][y - 1] = dist[x][y] + 1;
            q.push({x + 2, y - 1});
        }
        if (x + 2 <= n && y + 1 <= n && !used[x + 2][y + 1]) {
            used[x + 2][y + 1] = 1;
            dist[x + 2][y + 1] = dist[x][y] + 1;
            q.push({x + 2, y + 1});
        }
    }

    cout << dist[f2][s2] << endl;
    return 0;
}