10653.cpp

/**
 *                                   ____
 *       ____ ___  ____ ________  __/ __/
 *      / __ `__ \/ __ `/ ___/ / / / /_
 *     / / / / / / /_/ / /  / /_/ / __/
 *    /_/ /_/ /_/\__,_/_/   \__,_/_/
 *
 *    @link : https://the-redback.com
 */
#include <bits/stdc++.h>
using namespace std;

#define inf       HUGE_VAL
#define mem(a, b) memset(a, b, sizeof(a))
#define NN        1000
int a[NN + 7][NN + 7];
int dist[NN + 7][NN + 7];
queue<int> X;
queue<int> Y;
int dr[] = {0, -1, 0, 1};
int dc[] = {-1, 0, 1, 0};
int R, C;
int bfs(int srcx, int srcy, int dstx, int dsty) {
    X = queue<int>();
    Y = queue<int>();
    mem(dist, -1);
    X.push(srcx);
    Y.push(srcy);
    dist[srcx][srcy] = 0;
    while (!X.empty()) {
        int xx = X.front();
        int yy = Y.front();
        X.pop();
        Y.pop();
        for (int i = 0; i < 4; i++) {
            int x = xx + dr[i];
            int y = yy + dc[i];
            if (x < 0 || y < 0 || x >= R || y >= C) continue;
            if (dist[x][y] == -1 && a[x][y] == 0) {
                X.push(x);
                Y.push(y);
                dist[x][y] = dist[xx][yy] + 1;
                if (x == dstx && y == dsty) return dist[x][y];
            }
        }
    }
    return 0;
}

int main() {
    // freopen("C:\\Users\\Maruf Tuhin\\Desktop\\in.txt","r",stdin);
    int i, j, k, l, n, r, c;
    int tc, t = 1;
    // scanf("%d",&tc);
    while (~scanf("%d%d", &R, &C)) {
        if (R == 0 && C == 0) return 0;
        mem(a, 0);
        scanf("%d", &n);
        for (i = 0; i < n; i++) {
            scanf("%d%d", &r, &k);
            while (k--) scanf("%d", &c), a[r][c] = 1;
        }
        int srcx, srcy, dstx, dsty;
        scanf("%d%d%d%d", &srcx, &srcy, &dstx, &dsty);
        int sum = bfs(srcx, srcy, dstx, dsty);
        printf("%d\n", sum);
    }
    return 0;
}