// includes #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include // macros #define ll long long int #define pb emplace_back #define mk make_pair #define pq priority_queue #define FOR(i, a, b) for(int i=(a);i<(b);++i) #define rep(i, n) FOR(i, 0, n) #define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--) #define all(x) (x).begin(),(x).end() #define sz(x) ((int)(x).size()) #define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end()) using namespace std; // types typedef pair P; typedef pair Pl; typedef pair Pll; typedef pair Pd; // constants const int inf = 1e9; const ll linf = 1LL << 50; const double EPS = 1e-10; const int mod = 1e9 + 7; // solve template bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;} template bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;} template struct Graph_ { int n; vector > > edge; vector dis; Graph_(int ns) { n = ns; edge.resize(n); dis.resize(n); } void dijkstra(int s){ dijkstra(s, 0); } T dijkstra(int s, int t){ // initialize fill(dis.begin(), dis.end(), -1); vector used; used.resize(n); fill(used.begin(), used.end(), false); dis[s] = 0; // dijkstra priority_queue, vector >, greater > > q; q.push(make_pair(0, s)); while(!q.empty()){ pair p = q.top(); q.pop(); int at = p.second; T distance = p.first; if(used[at])continue; used[at] = true; for(auto itr = edge[at].begin(); itr != edge[at].end(); ++itr){ int to = (*itr).first; T cost = (*itr).second; if(used[to])continue; if(dis[to] == -1 || dis[to] > distance + cost){ q.push(make_pair(distance + cost, to)); dis[to] = distance + cost; } } } return dis[t]; } void adde(int at, int to, T cost){ edge[at].push_back(make_pair(to, cost)); } [[deprecated("This function takes O(edge[at].size()).")]] void remove(int at, int to){ int index = -1; for(int i = 0; i < edge[at].size(); i++){ if(edge[at][i].first == to){ index = i; break; } } edge[at].erase(edge[at].begin() + index); } }; typedef struct Graph_ GraphI; typedef struct Graph_ GraphL; typedef struct Graph_ GraphD; int l[201][201]; int dx[4] = {-1, 0, 1, 0}; int dy[4] = {0, -1, 0, 1}; int main(int argc, char const* argv[]) { ios_base::sync_with_stdio(false); cin.tie(0); int n, v; cin >> n >> v; int ox, oy; cin >> ox >> oy, ox--, oy--; rep(i, n){ rep(j, n)cin >> l[j][i]; } GraphI graph(n * n); for(int i = 0; i < n; i++){ for(int j = 0; j < n; j++){ for(int k = 0; k < 4; k++){ int nx = i + dx[k]; int ny = j + dy[k]; if(nx >= 0 && nx < n && ny >= 0 && ny < n){ graph.adde(i * n + j, nx * n + ny, l[nx][ny]); graph.adde(nx * n + ny, i * n + j, l[i][j]); } } } } graph.dijkstra(0); if(v > l[0][0] + graph.dis[n * n - 1]){ cout << "YES" << endl; return 0; } if(ox >= 0 && oy >= 0 && v > graph.dis[ox * n + oy]){ ll tmp = 2 * (v - graph.dis[ox * n + oy]); tmp -= graph.dijkstra(ox * n + oy, n * n - 1); if(tmp > 0){ cout << "YES" << endl; return 0; } } cout << "NO" << endl; return 0; }